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Exchange Server error library

Exchange Server errors, NDRs and event IDs — and how to fix them

Search 860 errors from 127 guides for Exchange Server SE, 2019 and 2016, Exchange hybrid and the third-party products around Exchange — email security gateways, backup, archiving and DLP. Paste the exact text you see — an NDR code, a queue LastError, an event ID, a setup, OWA or backup message — and open the guide that fixes it.

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Showing all 860 errors

Mail flow

NDRs, queues, connectors, relay, TLS and message tracking

54
4.4.0 DNS query failedTransport queue (mail stuck in Drafts)451 4.4.0 DNS query failed: fixing Exchange queues stuck in Retry 5.7.1 Delivery not authorized, message refusedNDR (rule rejection, default text)Exchange Server transport rules not applying: priorities, conditions and how to test 421 4.4.2 Connection dropped due to SocketErrorGet-Queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues 421 4.4.2 Connection dropped due to SocketErrorQueue Viewer / Get-Queue LastErrorSMTP protocol logging on Exchange: reading send and receive logs to debug connections 441 4.4.1 Error encountered while communicating with primary target IP addressQueue Viewer / Get-Queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues 451 4.4.0 DNS query failedQueue Viewer / Get-Queue LastError451 4.4.0 DNS query failed: fixing Exchange queues stuck in Retry 451 4.4.0 DNS query failed. The error was: SMTPSEND.DNS.NonExistentDomain; nonexistent domainGet-Queue LastError451 4.4.0 DNS query failed: fixing Exchange queues stuck in Retry 451 4.4.0 Error encountered while communicating with primary target IP addressGet-Queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues 451 5.7.3 Must issue a STARTTLS command firstSMTP send or receive protocol logSMTP protocol logging on Exchange: reading send and receive logs to debug connections 452 4.3.1 Insufficient system resourcesNDR / sending server queue452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed 454 4.7.5 The certificate specified in TlsCertificateName of the SendConnector could not be foundQueue Viewer / Get-Queue LastErrorEvent ID 12014: Exchange can't find a TLS certificate for a connector FQDN 530 5.7.1 Client was not authenticatedDevice, app or telnet SMTP session530 5.7.1 Client was not authenticated: fixing anonymous SMTP submission to Exchange 530 5.7.1 Client was not authenticatedSMTP receive protocol log530 5.7.1 Client was not authenticated: fixing anonymous SMTP submission to Exchange 535 5.7.3 Authentication unsuccessfulSMTP receive protocol logSMTP protocol logging on Exchange: reading send and receive logs to debug connections 550 4.4.7 QUEUE.Expired; message expiredNDR441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues 550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not foundNDR (Exchange Server)550 5.1.1 RESOLVER.ADR.ExRecipNotFound and IMCEAEX NDRs: fixing them with X500 addresses 550 5.1.11 RESOLVER.ADR.ExRecipNotFound; Recipient not found by Exchange Legacy encapsulated email address lookupNDR (Exchange Online / hybrid)550 5.1.1 RESOLVER.ADR.ExRecipNotFound and IMCEAEX NDRs: fixing them with X500 addresses 550 5.2.3 RESOLVER.RST.RecipSizeLimit; message too large for this recipientNDR550 5.3.4 ROUTING.SizeLimit and 5.2.3: every Exchange message size limit in one place 550 5.3.4 ROUTING.SizeLimit; message size exceeds fixed maximum size for routeNDR / Get-MessageTrackingLog550 5.3.4 ROUTING.SizeLimit and 5.2.3: every Exchange message size limit in one place 550 5.7.1 Unable to relayTelnet / SMTP session550 5.7.54 Unable to relay: configuring anonymous relay on Exchange Server safely 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domainSMTP session / application log550 5.7.54 Unable to relay: configuring anonymous relay on Exchange Server safely 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domainSMTP receive protocol logSMTP protocol logging on Exchange: reading send and receive logs to debug connections 554 5.4.6 Hop count exceeded - possible mail loopNDR (on-premises Exchange)554 5.4.6 and 5.4.14 Hop count exceeded: finding and fixing Exchange mail loops 554 5.4.14 Hop count exceeded - possible mail loop ATTR34NDR (Exchange Online / hybrid)554 5.4.6 and 5.4.14 Hop count exceeded: finding and fixing Exchange mail loops Attempted failover to alternate host, but that did not succeed.Get-Queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues couldn't create or update the Edge Subscription account on the Edge Transport serverNew-EdgeSubscription on the Edge serverEdgeSync failing with "The LDAP server is unavailable": re-creating the Edge Subscription DNS query failed with error InfoNoRecordsGet-Queue LastError451 4.4.0 DNS query failed: fixing Exchange queues stuck in Retry EdgeSync service cannot connect to this subscription because of error "The LDAP server is unavailable."Test-EdgeSynchronizationEdgeSync failing with "The LDAP server is unavailable": re-creating the Edge Subscription Either there are no alternate hosts, or delivery failed to all alternate hosts.Get-Queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues Event ID 1000 (Application Error)Application logPoison message queue and a stuck Submission queue in Exchange: causes and safe fixes Event ID 4999 (MSExchange Common)Application logPoison message queue and a stuck Submission queue in Exchange: causes and safe fixes Event ID 12014 (MSExchangeFrontEndTransport or MSExchangeTransport)Application logEvent ID 12014: Exchange can't find a TLS certificate for a connector FQDN Event ID 15004 (MSExchangeTransport): Resource pressure increasedApplication log452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed Event ID 15005 (MSExchangeTransport): Resource pressure decreasedApplication log452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed Event ID 15006 (MSExchangeTransport)Application log452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed Event ID 15007 (MSExchangeTransport)Application log452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed EX01\Poison (NextHopDomain: Poison Message), messages SuspendedQueue Viewer / Get-QueuePoison message queue and a stuck Submission queue in Exchange: causes and safe fixes EX01\Submission (NextHopDomain: Submission) not drainingGet-Queue: MessageCount up, Velocity negativePoison message queue and a stuck Submission queue in Exchange: causes and safe fixes Failed to connect. Winsock error code: 10060, Win32 error code: 10060.Get-Queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues Faulting application name: EdgeTransport.exeApplication log (Event ID 1000)Poison message queue and a stuck Submission queue in Exchange: causes and safe fixes IMCEAEX-_O=<org>_OU=EXCHANGE+20ADMINISTRATIVE+20GROUP+20+28FYDIBOHF23SPDLT+29_CN=RECIPIENTS_CN=<id>@<domain>NDR recipient address550 5.1.1 RESOLVER.ADR.ExRecipNotFound and IMCEAEX NDRs: fixing them with X500 addresses Microsoft Exchange could not find a certificate that contains the domain name mail.contoso.com in the personal store on the local computer.Event ID 12014 descriptionEvent ID 12014: Exchange can't find a TLS certificate for a connector FQDN POISONMESSAGEGet-MessageTrackingLog EventIdPoison message queue and a stuck Submission queue in Exchange: causes and safe fixes Remote Server returned '550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found'NDR (diagnostic section)550 5.1.1 RESOLVER.ADR.ExRecipNotFound and IMCEAEX NDRs: fixing them with X500 addresses The LDAP server is unavailable.New-EdgeSubscription / Test-EdgeSynchronizationEdgeSync failing with "The LDAP server is unavailable": re-creating the Edge Subscription The Microsoft Exchange Transport service is rejecting message submissions because the service continues to consume more memoryApplication log (Event ID 15007)452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed The Microsoft Exchange Transport service is rejecting messages because available disk space is below the configured threshold.Application log (Event ID 15006)452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed Therefore, it is unable to support the STARTTLS SMTP verb for the connectorEvent ID 12014 descriptionEvent ID 12014: Exchange can't find a TLS certificate for a connector FQDN TLS negotiation failed with error AlgorithmMismatchSMTP protocol logSMTP protocol logging on Exchange: reading send and receive logs to debug connections TLS negotiation failed with error NoCredentialsSMTP send protocol logSMTP protocol logging on Exchange: reading send and receive logs to debug connections TLS negotiation failed with error SocketErrorSMTP send protocol logSMTP protocol logging on Exchange: reading send and receive logs to debug connections TLS negotiation failed with error UnknownCredentialsSMTP send protocol logEvent ID 12014: Exchange can't find a TLS certificate for a connector FQDN TLS negotiation failed with error UnknownCredentialsSMTP send protocol logSMTP protocol logging on Exchange: reading send and receive logs to debug connections Watson report about to be sent for process idApplication log (Event ID 4999)Poison message queue and a stuck Submission queue in Exchange: causes and safe fixes

Databases & DAG

Mounting, corruption, transaction logs, replication, search and mailbox moves

59
554 5.2.2 mailbox full; STOREDRV.Deliver.Exception:QuotaExceededException.MapiExceptionShutoffQuotaExceededNDR (diagnostic information)Mailbox full in Exchange Server: quotas, ProhibitSendQuota and the 554 5.2.2 NDR -501 JET_errLogFileCorrupteseutil / Application log (ESE)Exchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery -528 JET_errMissingLogFileeseutil /rRestore mail from backup with an Exchange Server recovery database (RDB), step by step -550 JET_errDatabaseDirtyShutdowneseutil / Application log (ESE)Exchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery -1019 (JET_errPageNotInitialized)Application log (ESE event 476)JET error -1018 and ESE event 474: page checksum corruption in an Exchange database -1022 (JET_errDiskIO)Application log (ESE)JET error -1018 and ESE event 474: page checksum corruption in an Exchange database -1216 JET_errAttachedDatabaseMismatcheseutil / Application log (ESE)Exchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery -1216 JET_errAttachedDatabaseMismatcheseutil /rRestore mail from backup with an Exchange Server recovery database (RDB), step by step An Active Manager operation failed. Error: The database action failed.Mount-Database / EACExchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery Cluster node 'EX02' was removed from the active failover cluster membership.System log (Event ID 1135)DAG cluster problems: lost quorum, file share witness errors and Event ID 1135 CompletedWithWarningGet-MoveRequestStatistics StatusDetailStalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves ContentIndexState : FailedGet-MailboxDatabaseCopyStatusExchange content index Failed or Unknown: fixing search on Exchange 2016, 2019 and SE ContentIndexState : FailedAndSuspendedGet-MailboxDatabaseCopyStatusExchange content index Failed or Unknown: fixing search on Exchange 2016, 2019 and SE ContentIndexState : UnknownGet-MailboxDatabaseCopyStatusExchange content index Failed or Unknown: fixing search on Exchange 2016, 2019 and SE Couldn't mount the database that you specified.Exchange admin center (EAC)Exchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery Database recovery/restore failed with unexpected error -510.Application log (ESE)Exchange transaction logs filling the disk: backups, circular logging and safe recovery DBCopyFailed *FAILED*Test-ReplicationHealthDatabase copy FailedAndSuspended in an Exchange DAG: find the cause and reseed safely DBCopySuspended *FAILED*Test-ReplicationHealthDatabase copy FailedAndSuspended in an Exchange DAG: find the cause and reseed safely DBDisconnected *FAILED*Test-ReplicationHealthHigh CopyQueueLength or ReplayQueueLength in an Exchange DAG: causes and fixes DBLogCopyKeepingUp *FAILED*Test-ReplicationHealthHigh CopyQueueLength or ReplayQueueLength in an Exchange DAG: causes and fixes DBLogReplayKeepingUp *FAILED*Test-ReplicationHealthHigh CopyQueueLength or ReplayQueueLength in an Exchange DAG: causes and fixes DisconnectedAndHealthyGet-MailboxDatabaseCopyStatusHigh CopyQueueLength or ReplayQueueLength in an Exchange DAG: causes and fixes DisconnectedAndResynchronizingGet-MailboxDatabaseCopyStatusHigh CopyQueueLength or ReplayQueueLength in an Exchange DAG: causes and fixes Event ID 413 (ESE)Application logExchange transaction logs filling the disk: backups, circular logging and safe recovery Event ID 474 (ESE)Application logJET error -1018 and ESE event 474: page checksum corruption in an Exchange database Event ID 476 (ESE)Application logJET error -1018 and ESE event 474: page checksum corruption in an Exchange database Event ID 1135 (Microsoft-Windows-FailoverClustering)System logDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 Event ID 1177 (Microsoft-Windows-FailoverClustering)System logDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 Event ID 10047 (MSExchangeIS Mailbox Store)Application logNew-MailboxRepairRequest: fixing logical corruption in Exchange mailboxes Event ID 10048 (MSExchangeIS Mailbox Store)Application logNew-MailboxRepairRequest: fixing logical corruption in Exchange mailboxes Event ID 10059 (MSExchangeIS Mailbox Store)Application logNew-MailboxRepairRequest: fixing logical corruption in Exchange mailboxes Event ID 10062 (MSExchangeIS Mailbox Store)Application logNew-MailboxRepairRequest: fixing logical corruption in Exchange mailboxes failed verification because it contains no page dataApplication log (ESE event 476)JET error -1018 and ESE event 474: page checksum corruption in an Exchange database failed verification due to a page checksum mismatchApplication log (ESE event 474)JET error -1018 and ESE event 474: page checksum corruption in an Exchange database FailedAndSuspendedGet-MailboxDatabaseCopyStatusDatabase copy FailedAndSuspended in an Exchange DAG: find the cause and reseed safely FileShareQuorum *FAILED*Test-ReplicationHealthDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 MapiExceptionDatabaseError: Unable to mount database. (hr=0x80004005, ec=1108)Mount-Database / EACExchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery MapiExceptionJetErrorMissingLogFile: Unable to mount database. (hr=0x80004005, ec=-528)Mount-DatabaseExchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery Page patching was initiated to restore the page.Application log (ExchangeStoreDB)JET error -1018 and ESE event 474: page checksum corruption in an Exchange database Please verify that the Microsoft Search (Exchange) and the Host Controller service for Exchange services are runningUpdate-MailboxDatabaseCopyExchange content index Failed or Unknown: fixing search on Exchange 2016, 2019 and SE Relinquishing job because of large delays due to unfavorable server health or budget limitationsMove request report (-IncludeReport)StalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves Search results may be incomplete because items are still being indexed.Outlook (Cached Exchange Mode)Exchange content index Failed or Unknown: fixing search on Exchange 2016, 2019 and SE SeedInProgressException error FE1C6491Update-MailboxDatabaseCopyDatabase copy FailedAndSuspended in an Exchange DAG: find the cause and reseed safely StalledDueToTarget_DiskLatencyGet-MoveRequestStatistics StatusDetailStalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves StalledDueToTarget_MdbAvailabilityGet-MoveRequestStatistics StatusDetailStalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves StalledDueToTarget_MdbReplicationGet-MoveRequestStatistics StatusDetailStalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves State: Dirty Shutdowneseutil /mhExchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery State: Dirty Shutdowneseutil /mh (restored database)Restore mail from backup with an Exchange Server recovery database (RDB), step by step The Cluster service is shutting down because quorum was lost.System log (Event ID 1177)DAG cluster problems: lost quorum, file share witness errors and Event ID 1135 The Exchange Trusted Subsystem is not a member of the local Administrators group on specified witness server FSW01.Set-DatabaseAvailabilityGroupDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 The message store has reached its maximum sizeOutlookMailbox full in Exchange Server: quotas, ProhibitSendQuota and the 554 5.2.2 NDR The read operation will fail with error -1018 (0xfffffc06).Application log (ESE)JET error -1018 and ESE event 474: page checksum corruption in an Exchange database The recipient's mailbox is full and can't accept messages now.NDR (user-facing text)Mailbox full in Exchange Server: quotas, ProhibitSendQuota and the 554 5.2.2 NDR The task was unable to create the default witness directory on server FSW01. Please manually specify a witness directory.New-DatabaseAvailabilityGroupDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 This mailbox exceeded the maximum number of corrupted items that were specified for this move request.Move request Message / EACStalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves TooManyBadItemsPermanentExceptionGet-MoveRequestStatistics FailureTypeStalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves Unable to access file shares on witness server FSW01.New/Set-DatabaseAvailabilityGroupDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 Unable to create a new logfile because the database cannot write to the log drive.Application log (ESE event 413)Exchange transaction logs filling the disk: backups, circular logging and safe recovery WARNING: Seeding of content index catalog for database 'DB01' failed.Update-MailboxDatabaseCopyExchange content index Failed or Unknown: fixing search on Exchange 2016, 2019 and SE

Setup & updates

Prerequisites, AD preparation, failed upgrades, services and server components

48
A Setup failure previously occurred while installing the HubTransportRole role.Exchange setup readiness checksSetup previously failed while performing the action: recovering a failed Exchange upgrade Cannot serialize contextExchange Management Shell (HTTP 400)Installing Exchange Server security updates: preparation, failures and post-install checks Cannot start the service Microsoft Exchange Service HostExchange setup (CU)Exchange services disabled or not starting after a CU or security update (error 1058) Cannot start the service Microsoft Exchange Service HostExchange setup (CU)Setup previously failed while performing the action: recovering a failed Exchange upgrade Could not load file or assembly 'Microsoft.Exchange.Common'OWA / ECP (HTTP 500)Installing Exchange Server security updates: preparation, failures and post-install checks Creating Native images for .NET assembliesSecurity update installerInstalling Exchange Server security updates: preparation, failures and post-install checks Database is mandatory on UserMailbox.Get-Mailbox -Arbitration / Exchange setupMissing Exchange arbitration mailboxes: the errors they cause and how to recreate them Error 1068: The dependency service or group failed to start.Services console (services.msc)Exchange services disabled or not starting after a CU or security update (error 1058) error 1619Exchange setupInstalling an Exchange cumulative update without surprises: a pre-flight checklist Error code 1603: The installer has insufficient privileges to access this directorySecurity update installerInstalling Exchange Server security updates: preparation, failures and post-install checks Event 15021System logInstalling Exchange Server security updates: preparation, failures and post-install checks Event ID 1006Application logExchange unstable after October 2026 Windows Server updates: MdbOffline and the RPC fix Event ID 2937 (MSExchange ADAccess)Application logUninstalling an old Exchange server: mailboxes, connectors and errors that block removal Event ID 7000 (Service Control Manager)System logExchange services disabled or not starting after a CU or security update (error 1058) Event ID 7001: The <service> service depends on the <service> service which failed to startSystem log (Service Control Manager)Exchange services disabled or not starting after a CU or security update (error 1058) Event ID 7040 (Service Control Manager)System logExchange services disabled or not starting after a CU or security update (error 1058) Exchange Server MaintenanceHealth Checker (yellow warning)Exchange components stuck Inactive after an update: ServerWideOffline and requesters Exchange services left Disabled after a failed updateServices consoleInstalling Exchange Server security updates: preparation, failures and post-install checks FrontendTransport InactiveGet-ServerComponentStateExchange components stuck Inactive after an update: ServerWideOffline and requesters HubTransport InactiveGet-ServerComponentStateExchange components stuck Inactive after an update: ServerWideOffline and requesters Insert the 'Microsoft Exchange Server' disk and click OK.Exchange setup (uninstall)Uninstalling an old Exchange server: mailboxes, connectors and errors that block removal isn't installed on this computer and needs to be installed before Exchange Setup can beginExchange setup readiness checksExchange setup prerequisite errors: UCMA, Visual C++, .NET, URL Rewrite, pending restart MapiExceptionMdbOffline: Unable to make connection to the server. (hr=0x80004005, ec=1142)OWA / ECPExchange unstable after October 2026 Windows Server updates: MdbOffline and the RPC fix Microsoft Exchange Server setup cannot continue because a restart from a previous installation or update is pending.Exchange setupInstalling an Exchange cumulative update without surprises: a pre-flight checklist Microsoft Exchange Server setup cannot continue because a restart from a previous installation or update is pending.Exchange setupExchange setup prerequisite errors: UCMA, Visual C++, .NET, URL Rewrite, pending restart points to an invalid DN or a deleted object. Remove the entry, and then rerun the task.Exchange setup / PrepareADExchange PrepareSchema and PrepareAD errors: permissions, schema master and AD versions Prerequisite Analysis FAILEDExchange setup (unattended)Exchange setup prerequisite errors: UCMA, Visual C++, .NET, URL Rewrite, pending restart Scripting Agent initialization failedExchange setupExchange Server disaster recovery: rebuild a lost server with Setup /Mode:RecoverServer ServerWideOffline InactiveGet-ServerComponentStateExchange components stuck Inactive after an update: ServerWideOffline and requesters setup can't create them because the local computer isn't in the same domain and site as the schema masterExchangeSetup.logExchange PrepareSchema and PrepareAD errors: permissions, schema master and AD versions Setup encountered a problem while validating the state of Active DirectoryExchangeSetup.logInstalling an Exchange cumulative update without surprises: a pre-flight checklist Setup encountered a problem while validating the state of Active DirectoryExchangeSetup.logExchange PrepareSchema and PrepareAD errors: permissions, schema master and AD versions Setup previously failed while performing the actionExchange setupSetup previously failed while performing the action: recovering a failed Exchange upgrade Setup previously failed while performing the action "BuildToBuildUpgrade". You can't resume setup by performing the action "Install".Exchange setupSetup previously failed while performing the action: recovering a failed Exchange upgrade Setup previously failed while performing the action "BuildToBuildUpgrade". You can't resume setup by performing the action "Uninstall".Exchange setupSetup previously failed while performing the action: recovering a failed Exchange upgrade Setup previously failed while performing the action "Install". You can't resume setup by performing the action "BuildToBuildUpgrade".Exchange setupSetup previously failed while performing the action: recovering a failed Exchange upgrade System error 1058 has occurred.net startExchange services disabled or not starting after a CU or security update (error 1058) The Active Directory schema isn't up-to-date, and this user account isn't a member of the 'Schema Admins' and/or 'Enterprise Admins' groups.Exchange setup readiness checksExchange PrepareSchema and PrepareAD errors: permissions, schema master and AD versions The Exchange Server setup operation didn't complete.Exchange setupSetup previously failed while performing the action: recovering a failed Exchange upgrade The feature you are trying to use is on a CD-ROM or other removable disk that is not available.Exchange setup (uninstall)Uninstalling an old Exchange server: mailboxes, connectors and errors that block removal The Microsoft Exchange administrator has made a change that requires you quit and restart Outlook.Outlook (after a mailbox move)Exchange 2016 to Exchange Server SE migration: coexistence, namespaces and decommissioning The operation couldn't be performed because object 'Migration.8f3e7716-2011-43e4-96b1-aba62d229136' couldn't be foundExchange Management ShellMissing Exchange arbitration mailboxes: the errors they cause and how to recreate them The service cannot be started, either because it is disabled or because it has no enabled devices associated with it.net start / System logExchange services disabled or not starting after a CU or security update (error 1058) The upgrade patch cannot be installed by the Windows Installer serviceSecurity update installerInstalling Exchange Server security updates: preparation, failures and post-install checks The upgrade patch cannot be installed by the Windows Installer service because the program to be upgraded might be missingSecurity update installerInstalling an Exchange cumulative update without surprises: a pre-flight checklist this Interim Update is incompatible with the currentSecurity update installerInstalling Exchange Server security updates: preparation, failures and post-install checks This mailbox database contains one or more mailboxes, mailbox plans, archive mailboxes, public folder mailboxes or arbitration mailboxesExchange setup / Remove-MailboxDatabaseUninstalling an old Exchange server: mailboxes, connectors and errors that block removal Windows could not start the Microsoft Exchange Information Store service on Local Computer.Services console (services.msc)Exchange services disabled or not starting after a CU or security update (error 1058)

Certificates & security

Certificates, TLS, authentication, Extended Protection and hardening

15
-1032 JET_errFileAccessDeniedApplication log (ESE)Antivirus on Exchange Server: the exclusions Microsoft documents and how to test them [Owa] An internal server error occurred. The unhandled exception was: System.NullReferenceExceptionApplication log (Event ID 1003)Expired Exchange Auth certificate: OWA/EAC redirect loops, Event ID 1003 and hybrid errors A special Rpc error occurs on server <Servername>: The certificate with thumbprint <AuthCertificateThumbprint> was not found.Exchange Management ShellExpired Exchange Auth certificate: OWA/EAC redirect loops, Event ID 1003 and hybrid errors at Microsoft.Exchange.HttpProxy.FbaModule.ParseCadataCookiesEvent ID 1003 detailsExpired Exchange Auth certificate: OWA/EAC redirect loops, Event ID 1003 and hybrid errors Backdoor:ASP/SecChecker.AMicrosoft Defender AntivirusIs my Exchange server compromised? Checking with Microsoft's CSS-Exchange scripts Download failed and temporary fileOABGeneratorLogIs my Exchange server compromised? Checking with Microsoft's CSS-Exchange scripts ERR_TOO_MANY_REDIRECTSBrowser (OWA / EAC sign-in)Expired Exchange Auth certificate: OWA/EAC redirect loops, Event ID 1003 and hybrid errors Event ID 1003 (MSExchange Front End HTTPS Proxy [Owa])Application logExpired Exchange Auth certificate: OWA/EAC redirect loops, Event ID 1003 and hybrid errors Event ID 1008 (MSExchange Mitigation Service)Application logExchange Emergency Mitigation service and AMSI: how they protect on-premises servers Exploit:Script/Exmann.A!dhaMicrosoft Defender AntivirusIs my Exchange server compromised? Checking with Microsoft's CSS-Exchange scripts However, there is a problem with the site's security certificate.Outlook Security AlertOutlook “The name on the security certificate is invalid”: Exchange URLs vs SAN names NET::ERR_CERT_COMMON_NAME_INVALIDBrowser (OWA / EAC)Outlook “The name on the security certificate is invalid”: Exchange URLs vs SAN names The name on the security certificate is invalid or does not match the name of the siteOutlook Security AlertOutlook “The name on the security certificate is invalid”: Exchange URLs vs SAN names The page isn't redirecting properlyBrowser (Firefox, OWA / EAC sign-in)Expired Exchange Auth certificate: OWA/EAC redirect loops, Event ID 1003 and hybrid errors Trojan:JS/Chopper!dhaMicrosoft Defender detectionIs my Exchange server compromised? Checking with Microsoft's CSS-Exchange scripts

Client access

OWA, ECP, Outlook, Autodiscover, ActiveSync, EWS, the OAB and public folders

61
0x8004010FOutlook Send/ReceiveOffline address book not downloading in Outlook: fixing 0x8004010F and 0x80190194 0x80190194Outlook (Download Address Book)Offline address book not downloading in Outlook: fixing 0x8004010F and 0x80190194 401 Credentials rejectedIIS log (Microsoft-Server-ActiveSync)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 403 User not enabled for ActiveSyncIIS log (Microsoft-Server-ActiveSync)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 449 Device must apply the mailbox policy firstIIS log (Microsoft-Server-ActiveSync)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 451 Redirect: the mailbox is served elsewhereIIS log (Microsoft-Server-ActiveSync)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 500.19Browser / IIS log (OWA, ECP)OWA and ECP HTTP 500 errors on Exchange Server: usual causes and how to tell them apart 554 5.2.0 STOREDRV.Submission.Exception:SendAsDeniedException.MapiExceptionSendAsDeniedNDR (diagnostic information)554 5.2.0 SendAsDenied on Exchange Server: fixing Send As and Send on Behalf errors 12037 / 12038 / 12045Test E-mail AutoConfigurationAutodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors -ERR Logon failure: unknown user name or bad password.POP3 client / OutlookPOP3 and IMAP4 on Exchange Server: fixing NO LOGIN failed, missing banners and TLS errors An error occurred while using SSL configuration for endpoint 0.0.0.0:444System log (Event ID 15021)OWA and ECP broken after certificate changes: fixing the Exchange Back End 444 binding Autoconfiguration was unable to determine your settings!Test E-mail AutoConfigurationAutodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors Autodiscover to https://autodiscover.contoso.com/autodiscover/autodiscover.xml Failed (0x800C8203)Test E-mail AutoConfigurationAutodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors Cannot display folder. Network problems are preventing connection to Microsoft Exchange.Outlook (public folders)Public folders missing or not accessible in Outlook: hierarchy, mailboxes and permissions Cannot expand the folder.Outlook (public folders, online archive)"The connection to Microsoft Exchange is unavailable": fixing Outlook on Exchange Server Cannot expand the folder. The set of folders cannot be opened.Outlook (public folders)Public folders missing or not accessible in Outlook: hierarchy, mailboxes and permissions Client does not have permissions to send as this senderSMTP client / application554 5.2.0 SendAsDenied on Exchange Server: fixing Send As and Send on Behalf errors Could not load file or assembly 'Microsoft.Exchange.Common, Version=15.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'OWA / ECPOWA and ECP HTTP 500 errors on Exchange Server: usual causes and how to tell them apart DeviceAccessState : QuarantinedGet-MobileDeviceActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors DisconnectedOutlook status bar"The connection to Microsoft Exchange is unavailable": fixing Outlook on Exchange Server Enter the server FQDN where you want to connect.Exchange Management ShellOWA and ECP broken after certificate changes: fixing the Exchange Back End 444 binding ErrMsg=ProxyNotAuthenticatedIMAP4 protocol logPOP3 and IMAP4 on Exchange Server: fixing NO LOGIN failed, missing banners and TLS errors ErrorExceededConnectionCountEWS responseEWS errors on Exchange Server: 401, 503, ErrorServerBusy and impersonation failures ErrorExceededSubscriptionCountEWS responseEWS errors on Exchange Server: 401, 503, ErrorServerBusy and impersonation failures ErrorImpersonateUserDenied: The account does not have permission to impersonate the requested user.EWS responseEWS errors on Exchange Server: 401, 503, ErrorServerBusy and impersonation failures ErrorServerBusy: The server cannot service this request right now. Try again later.EWS responseEWS errors on Exchange Server: 401, 503, ErrorServerBusy and impersonation failures Event ID 4 (Security-Kerberos)System log (client PC)Outlook keeps prompting for a password with Exchange Server: the usual causes and fixes Event ID 1003: NullReferenceException at Microsoft.Exchange.HttpProxy.FbaModule.ParseCadataCookiesApplication logOWA and ECP HTTP 500 errors on Exchange Server: usual causes and how to tell them apart Event ID 1053 (MSExchange ActiveSync)Application logActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors Event ID 1309 (ASP.NET)Application logOWA and ECP HTTP 500 errors on Exchange Server: usual causes and how to tell them apart Event ID 15021 (HttpEvent)System logOWA and ECP broken after certificate changes: fixing the Exchange Back End 444 binding Event ID 15021 (HttpEvent)System logOWA and ECP HTTP 500 errors on Exchange Server: usual causes and how to tell them apart Exchange ActiveSync doesn't have sufficient permissions to create the "CN=..." container under Active Directory userApplication log (Event ID 1053)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors Failed to connect to an Exchange server in the current site.Exchange Management ShellOWA and ECP broken after certificate changes: fixing the Exchange Back End 444 binding GetLastError=12007; httpStatus=0Test E-mail AutoConfigurationAutodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors GetLastError=12029; httpStatus=0Test E-mail AutoConfigurationAutodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors httpStatus=401Test E-mail AutoConfigurationAutodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors ImapProxy InactiveGet-ServerComponentStatePOP3 and IMAP4 on Exchange Server: fixing NO LOGIN failed, missing banners and TLS errors KRB_AP_ERR_MODIFIEDSystem log (Event ID 4)Outlook keeps prompting for a password with Exchange Server: the usual causes and fixes Microsoft Exchange is not available. Either there are network problems or the Exchange server is down for maintenance.Outlook (public folders, online archive)"The connection to Microsoft Exchange is unavailable": fixing Outlook on Exchange Server Microsoft.Exchange.Monitoring.ProtocolException: Authentication failed. The connection is being closed.POP3/IMAP4 connection attemptPOP3 and IMAP4 on Exchange Server: fixing NO LOGIN failed, missing banners and TLS errors MicrosoftOffice16_Data:SSPICredential Manager (stale entry)Outlook keeps prompting for a password with Exchange Server: the usual causes and fixes NO AUTHENTICATE failed.IMAP4 clientPOP3 and IMAP4 on Exchange Server: fixing NO LOGIN failed, missing banners and TLS errors NO LOGIN failed.IMAP4 client / IMAP4 protocol logPOP3 and IMAP4 on Exchange Server: fixing NO LOGIN failed, missing banners and TLS errors Outlook repeatedly prompts for credentialsOutlookOutlook keeps prompting for a password with Exchange Server: the usual causes and fixes PopProxy InactiveGet-ServerComponentStatePOP3 and IMAP4 on Exchange Server: fixing NO LOGIN failed, missing banners and TLS errors problem 4003 (INSUFF_ACCESS_RIGHTS)Application log (Event ID 1053)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors Server Error in '/ecp' Application.ECP / EACOWA and ECP HTTP 500 errors on Exchange Server: usual causes and how to tell them apart something went wrong Sorry, we can't get that information right now. Please try again later.OWA / ECPOWA and ECP HTTP 500 errors on Exchange Server: usual causes and how to tell them apart Something went wrong Your request couldn't be completed. HTTP Status code: 500OWAOWA and ECP HTTP 500 errors on Exchange Server: usual causes and how to tell them apart Task '<account>' reported error (0x80190194): 'The operation failed.'Outlook (Download Address Book)Offline address book not downloading in Outlook: fixing 0x8004010F and 0x80190194 Task 'Microsoft Exchange Server' reported error (0x8004010F): 'The operation failed. An object could not be found.'Outlook Send/ReceiveOffline address book not downloading in Outlook: fixing 0x8004010F and 0x80190194 The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.Outlook (new profile)"The connection to Microsoft Exchange is unavailable": fixing Outlook on Exchange Server The Kerberos client received a KRB_AP_ERR_MODIFIED error from the serverSystem log (Event ID 4)Outlook keeps prompting for a password with Exchange Server: the usual causes and fixes The Microsoft Connectivity Analyzer failed to obtain an Autodiscover XML responseRemote Connectivity AnalyzerAutodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors The name on the security certificate is invalid or does not match the name of the siteOutlook security alertAutodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors The remote server returned an error: (401) Unauthorized.App log / integration errorEWS errors on Exchange Server: 401, 503, ErrorServerBusy and impersonation failures The remote server returned an error: (503) Server Unavailable.App log / integration errorEWS errors on Exchange Server: 401, 503, ErrorServerBusy and impersonation failures The WinRM Shell client cannot process the request. The shell handle passed to the WSMan Shell function is not valid.Exchange Management ShellOWA and ECP broken after certificate changes: fixing the Exchange Back End 444 binding You can't send a message on behalf of this user unless you have permission to do so.NDR554 5.2.0 SendAsDenied on Exchange Server: fixing Send As and Send on Behalf errors Your email server rejected your loginOutlook (POP3/IMAP4 account)POP3 and IMAP4 on Exchange Server: fixing NO LOGIN failed, missing banners and TLS errors

Management & monitoring

Exchange Management Shell, Managed Availability, event logs, performance and disk

43
5.7.1 RESOLVER.RST.AuthRequired; authentication requiredNDR (external sender)Exchange Server dynamic distribution groups: filter errors, missing members and previews 452 4.3.1 Insufficient system resourcesNDR / queue LastErrorHigh CPU or memory on Exchange Server: what's normal and how to find the real cause [FailureCategory=AuthZ-CmdletAccessDeniedException] The user "<user>" isn't assigned to any management roles.Exchange Management ShellExchange Server RBAC: roles, scopes and "access denied" in the EAC and shell A parameter cannot be found that matches parameter nameExchange Management ShellExchange Server RBAC: roles, scopes and "access denied" in the EAC and shell An existing permission entry was found for userAdd-MailboxFolderPermissionExchange Server calendar and folder permissions: Add-MailboxFolderPermission and delegates An unhandled exception occurred and the process was terminated.Application log (ASP.NET 1325)Event ID 4999 on Exchange Server: reading MSExchange Common Watson crash reports Cannot bind parameter 'RecipientFilter' to the target.Exchange Management ShellExchange Server dynamic distribution groups: filter errors, missing members and previews Event ID 258 (MSExchange RBAC)Application logExchange Server RBAC: roles, scopes and "access denied" in the EAC and shell Event ID 2004 (Resource-Exhaustion-Detector)System logHigh CPU or memory on Exchange Server: what's normal and how to find the real cause Event ID 2080 (MSExchange ADAccess)Application logTopology discovery failed (event 2142): reading event 2080 and fixing Exchange DC access Event ID 2112 (MSExchange ADAccess)Application logTopology discovery failed (event 2142): reading event 2080 and fixing Exchange DC access Event ID 2142 (MSExchangeADTopology)Application logTopology discovery failed (event 2142): reading event 2080 and fixing Exchange DC access Event ID 2937 (MSExchange ADAccess)Application logEvent ID 2937 MSExchange ADAccess: fixing HomeMTA and other links to deleted objects Event ID 4999 (MSExchange Common)Application logEvent ID 4999 on Exchange Server: reading MSExchange Common Watson crash reports Failed to connect to an Exchange server in the current site.Exchange Management Shell (startup)Exchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors Failed to connect to any Exchange Server in the current site.Exchange Management Shell (startup)Exchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors Insufficient access rights to perform the operation.Exchange Management Shell / EACExchange Server RBAC: roles, scopes and "access denied" in the EAC and shell Invalid filter syntax. For a description of the filter parameter syntax see the command help.New-/Set-DynamicDistributionGroupExchange Server dynamic distribution groups: filter errors, missing members and previews it is pointing to the Deleted Objects container in Active Directory. This property should be fixed as soon as possible.Application log (event 2937)Event ID 2937 MSExchange ADAccess: fixing HomeMTA and other links to deleted objects M.E.C.TimeoutCache.DuplicateKeyExceptionApplication log (event 4999)Event ID 4999 on Exchange Server: reading MSExchange Common Watson crash reports No Suitable Directory Servers Found in ForestApplication log (event 2142), OWA/ECPTopology discovery failed (event 2142): reading event 2080 and fixing Exchange DC access Property [HomeMTA] is set to value [contoso.com/Configuration/Deleted Objects/Microsoft MTA DEL:<GUID>]Application log (event 2937)Event ID 2937 MSExchange ADAccess: fixing HomeMTA and other links to deleted objects Property [HomeMtaServerId] is set to value [contoso.com/Configuration/Deleted Objects/Microsoft MTA DEL:<GUID>]Application log (event 2937)Event ID 2937 MSExchange ADAccess: fixing HomeMTA and other links to deleted objects Property [RecipientContainer] is set to value [contoso.com/Deleted Objects/<OU> DEL:<GUID>]Application log (event 2937)Event ID 2937 MSExchange ADAccess: fixing HomeMTA and other links to deleted objects System.OutOfMemoryExceptionApplication log (event 4999)Event ID 4999 on Exchange Server: reading MSExchange Common Watson crash reports System.UnauthorizedAccessExceptionApplication log (event 4999)Event ID 4999 on Exchange Server: reading MSExchange Common Watson crash reports The Exchange computer EX01.contoso.com does not have Audit Security Privilege on the domain controller DC02.contoso.com.Application log (ADAccess 2112)Topology discovery failed (event 2142): reading event 2080 and fixing Exchange DC access The following error with errorcode 0x80090322 occurred while using Kerberos authenticationExchange Management ShellExchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors The following messages were loaded at startup before Transport crashed.Application logEvent ID 4999 on Exchange Server: reading MSExchange Common Watson crash reports The process was terminated due to an unhandled exception.Application log (.NET Runtime 1026)Event ID 4999 on Exchange Server: reading MSExchange Common Watson crash reports The term 'New-MailboxExportRequest' is not recognized as the name of a cmdlet, function, script file, or operable program.Exchange Management ShellExchange Server RBAC: roles, scopes and "access denied" in the EAC and shell The WinRM client cannot process the request. It cannot determine the content type of the HTTP response from the destination computer.Exchange Management ShellExchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors The WinRM client received an HTTP server error status (500)Exchange Management ShellExchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors The WinRM client received an HTTP status code of 403 from the remote WS-Management service.Exchange Management ShellExchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors The WinRM client sent a request to an HTTP server and got a response saying the requested HTTP URL was not available.Exchange Management ShellExchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors There is no existing permission entry found for userSet-MailboxFolderPermissionExchange Server calendar and folder permissions: Add-MailboxFolderPermission and delegates This domain controller will not be used by Exchange Active Directory Provider.Application log (ADAccess 2112)Topology discovery failed (event 2142): reading event 2080 and fixing Exchange DC access Topology discovery failed, error details No Minimal Required Number of Suitable Directory Servers Found in ForestApplication log (event 2142)Topology discovery failed (event 2142): reading event 2080 and fixing Exchange DC access Unable to load the type "Microsoft.Exchange.Configuration.Authorization.ExchangeAuthorizationPlugin"Exchange Management ShellExchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors UserAlreadyExistsInPermissionEntryExceptionExchange Management ShellExchange Server calendar and folder permissions: Add-MailboxFolderPermission and delegates UserNotFoundInPermissionEntryExceptionExchange Management ShellExchange Server calendar and folder permissions: Add-MailboxFolderPermission and delegates Watson report about to be sent for process idApplication log (event 4999)Event ID 4999 on Exchange Server: reading MSExchange Common Watson crash reports Windows successfully diagnosed a low virtual memory condition. The following programs consumed the most virtual memory:System log (Event ID 2004)High CPU or memory on Exchange Server: what's normal and how to find the real cause

Hybrid & migration

Hybrid Configuration Wizard, hybrid mail flow, free/busy, migrations and the last server

33
5.4.1NDR (mail to migrated public folders)Migrating public folders to Exchange Online: the batch steps and the errors that stop them 5.7.13NDR (mail to migrated public folders)Migrating public folders to Exchange Online: the batch steps and the errors that stop them 454 4.7.5 The certificate specified in TlsCertificateName of the SendConnector could not be foundQueue LastErrorRenewing the Exchange hybrid certificate without breaking mail flow 550 5.1.10 "recipient not found"NDR (Exchange Online)Remote mailboxes in Exchange hybrid: Enable-RemoteMailbox, attributes and common mistakes 550 5.7.68 TenantInboundAttribution; Direct Send not allowed for this organization from unauthorized sourcesNDRExchange Server to Exchange Online: every scenario, from first batch to last server AADSTS500011 ("The resource principal named ... was not found in the tenant")Outlook sign-in / Microsoft Entra sign-in logHybrid Modern Authentication for Exchange Server: enable HMA and validate Outlook sign-in Active Directory must be prepared with 'Setup /PrepareAD' before Exchange Server management tools can be updated to a newer CU.Exchange setup (management tools only)Exchange Server to Exchange Online: every scenario, from first batch to last server Cannot find a recipient that has mailbox GUIDNew-MigrationBatch (Exchange Online)Migrating public folders to Exchange Online: the batch steps and the errors that stop them Could not updateOutlook (shared calendar)Hybrid free/busy not working: OAuth, the dedicated hybrid app and Test-OAuthConnectivity Couldn't find the public folder mailbox.Get-PublicFolder (after lock-down)Migrating public folders to Exchange Online: the batch steps and the errors that stop them DataStrings.InvalidSmtpDomainNameHybrid Configuration WizardHybrid Configuration Wizard failures: reading the HCW log and fixing common errors Error: Dumpster of the Dumpster folder.Public folder migration requestMigrating public folders to Exchange Online: the batch steps and the errors that stop them Execution of the <cmdlet> cmdlet had thrown an exceptionHybrid Configuration WizardHybrid Configuration Wizard failures: reading the HCW log and fixing common errors Free/busy error 5016 (couldn't be contacted)OWA Scheduling AssistantHybrid free/busy not working: OAuth, the dedicated hybrid app and Test-OAuthConnectivity Free/busy error 5037 (no permission to see free/busy)OWA Scheduling AssistantHybrid free/busy not working: OAuth, the dedicated hybrid app and Test-OAuthConnectivity Free/busy error 5039 (attendee's server couldn't be found)OWA Scheduling AssistantHybrid free/busy not working: OAuth, the dedicated hybrid app and Test-OAuthConnectivity HCW8064: The HCW has completed, but was not able to perform the OAuth portion of your Hybrid configurationHybrid Configuration WizardHybrid Configuration Wizard failures: reading the HCW log and fixing common errors MigrationPermanentException: The target mailbox doesn't have an SMTP proxy matching 'contoso.mail.onmicrosoft.com'Migration batch userHybrid mailbox migration batches: reading statuses, fixing common errors and completing the move need to be addressed or potentially configured manuallyHybrid Configuration WizardHybrid Configuration Wizard failures: reading the HCW log and fixing common errors No active public folder mailboxes were foundComplete-MigrationBatchMigrating public folders to Exchange Online: the batch steps and the errors that stop them PowerShell failed to invoke 'Set-FederatedOrganizationIdentifier'HCW logHybrid Configuration Wizard failures: reading the HCW log and fixing common errors Request was quarantined because of the following error: The given key wasn't present in the dictionary.Public folder migration requestMigrating public folders to Exchange Online: the batch steps and the errors that stop them SendAsDeniedExceptionNDR / message trackingCross-premises permissions in Exchange hybrid: Full Access, Send As and delegates Synced with errors / Completed with errorsMigration batch statusHybrid mailbox migration batches: reading statuses, fixing common errors and completing the move The authentication header received from the server was 'NTLM,Negotiate'.Migration endpoint / batch errorHybrid migration endpoint "could not be completed": fixing MRSProxy and 401 errors The call to 'https://mail.contoso.com/EWS/mrsproxy.svc' timed out.HCW log / migration endpointHybrid migration endpoint "could not be completed": fixing MRSProxy and 401 errors The command completed successfully but no settings have been modifiedSet-SendConnector / Set-ReceiveConnectorRenewing the Exchange hybrid certificate without breaking mail flow The connection to the server 'mail.contoso.com' could not be completed.Test-MigrationServerAvailability / HCWHybrid migration endpoint "could not be completed": fixing MRSProxy and 401 errors The HTTP request is unauthorized with client authentication scheme 'Negotiate'Migration endpoint / MRSProxyHybrid mailbox migration batches: reading statuses, fixing common errors and completing the move The HTTP request is unauthorized with client authentication scheme 'Negotiate'.Migration endpoint / batch errorHybrid migration endpoint "could not be completed": fixing MRSProxy and 401 errors The Mailbox Replication Service was unable to connect to the remote server using the credentials provided.Test-MigrationServerAvailability / HCWHybrid migration endpoint "could not be completed": fixing MRSProxy and 401 errors The remote server returned an error: (401) Unauthorized.Test-MigrationServerAvailabilityHybrid migration endpoint "could not be completed": fixing MRSProxy and 401 errors The underlying connection was closed: An unexpected error occurred on a send.HCW logHybrid Configuration Wizard failures: reading the HCW log and fixing common errors

Lifecycle

Exchange Server SE, end of support, upgrade paths and known issues

5
A ContentEngine deadlock occurs because of missing Korean WordBreaker rule files.Exchange search / indexingExchange Server known issues in 2026: what's open, what's fixed and how to stay informed A published calendar (.ics) returns "HTTP 500" for calendar applications.Calendar apps / IIS logExchange Server known issues in 2026: what's open, what's fixed and how to stay informed Availability (free/busy) fails for delegated mailboxes in Exchange hybrid deployments that use Graph API only.Outlook Scheduling Assistant (hybrid)Exchange Server known issues in 2026: what's open, what's fixed and how to stay informed Hybrid free/busy through Microsoft Graph incorrectly shifts busy times by requester timezone.Outlook Scheduling Assistant (hybrid)Exchange Server known issues in 2026: what's open, what's fixed and how to stay informed Wrapper messages appear in a shared mailbox in hybrid environments after installing the June 2026 Security Update.Shared mailbox (hybrid)Exchange Server known issues in 2026: what's open, what's fixed and how to stay informed

Third-party integrations

Email security gateways, backup, archiving, DLP, signature services and load balancers

88
5.3.190 Journaling on-premises messages to Microsoft 365 or Office 365 not supported when Journaling Archive is disabledNDR in the alternate journaling mailboxExchange Server journaling to Mimecast, Barracuda or Proofpoint: rules, connectors, NDRs 421 4.3.2 The maximum number of concurrent server connections has exceeded a per-source limit, closing transmission channelCisco Message Tracking (Exchange reply)Cisco Secure Email Gateway (IronPort) with Exchange Server: HAT, RAT and SMTP errors 421 4.3.2 The maximum number of concurrent server connections has exceeded a per-source limit, closing transmission channelProofpoint log (Exchange reply)Proofpoint with Exchange Server: connectors, TLS and the rejections admins see 421 4.3.2 The maximum number of concurrent server connections has exceeded a per-source limit, closing transmission channelGateway delivery log (Exchange reply)Email gateway in front of Exchange Server: connectors, InternalSMTPServers and loops 421 Exceeded allowable connection time, disconnecting.Get-Queue LastError (Cisco reply)Cisco Secure Email Gateway (IronPort) with Exchange Server: HAT, RAT and SMTP errors 421 Timed out waiting for successful message injection, disconnecting.Get-Queue LastError (Cisco reply)Cisco Secure Email Gateway (IronPort) with Exchange Server: HAT, RAT and SMTP errors 441 4.4.1 Error encountered while communicating with primary target IP addressGet-Queue LastError (to Barracuda)Barracuda Email Protection with Exchange Server: connectors, smart host and 550 rejections 441 4.4.1 Error encountered while communicating with primary target IP addressGet-Queue LastError (to FortiMail)FortiMail with Exchange Server: 550 5.7.1 Relay access denied, 451 and recipient checks 441 4.4.1 Error encountered while communicating with primary target IP addressQueue Viewer / Get-Queue LastErrorSymantec DLP Network Prevent for Email with Exchange Server: modes, loops and queue errors 441 4.4.1 Error encountered while communicating with primary target IP addressQueue Viewer / Get-Queue LastErrorDLP and encryption gateways for Exchange Server (Forcepoint, Trellix): routing and loops 451 5.7.3 Must issue a STARTTLS command firstCisco mail logs (Exchange reply)Cisco Secure Email Gateway (IronPort) with Exchange Server: HAT, RAT and SMTP errors 451 5.7.3 Must issue a STARTTLS command firstGateway delivery log (Exchange reply)Email gateway in front of Exchange Server: connectors, InternalSMTPServers and loops 451 An open relay is not allowedGet-Queue LastError (Mimecast smart host)Mimecast with Exchange Server: 451 Open relay not allowed, connectors and rejection codes 451 Try again laterSending server queue (FortiMail reply)FortiMail with Exchange Server: 550 5.7.1 Relay access denied, 451 and recipient checks 452 4.3.1 Insufficient system resourcesSMTP receive protocol log (from Barracuda)Barracuda Email Protection with Exchange Server: connectors, smart host and 550 rejections 452 4.3.1 Insufficient system resourcesProofpoint log (Exchange reply)Proofpoint with Exchange Server: connectors, TLS and the rejections admins see 452 Too many recipients received this hourSender's queue or delay notice (Cisco reply)Cisco Secure Email Gateway (IronPort) with Exchange Server: HAT, RAT and SMTP errors 454 4.7.5 The certificate specified in TlsCertificateName of the SendConnector could not be foundGet-Queue LastError (to Proofpoint)Proofpoint with Exchange Server: connectors, TLS and the rejections admins see 535 Incorrect authentication dataSMTP send protocol logMimecast with Exchange Server: 451 Open relay not allowed, connectors and rejection codes 550 4.4.7 QUEUE.Expired; message expiredNDRSymantec DLP Network Prevent for Email with Exchange Server: modes, loops and queue errors 550 5.1.1 RESOLVER.ADR.RecipNotFound; not foundNDR from ExchangeCisco Secure Email Gateway (IronPort) with Exchange Server: HAT, RAT and SMTP errors 550 5.1.1 RESOLVER.ADR.RecipNotFound; not foundNDR from ExchangeProofpoint with Exchange Server: connectors, TLS and the rejections admins see 550 5.7.1 Relay access deniedNDR / message tracking (FortiMail reply)FortiMail with Exchange Server: 550 5.7.1 Relay access denied, 451 and recipient checks 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domainSMTP receive protocol log (from Barracuda)Barracuda Email Protection with Exchange Server: connectors, smart host and 550 rejections 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domainCisco Message Tracking (Exchange reply)Cisco Secure Email Gateway (IronPort) with Exchange Server: HAT, RAT and SMTP errors 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domainSignature service log / NDREmail signatures on Exchange Server (Exclaimer, CodeTwo): routing, duplicates and NDRs 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domainSMTP client / app relaying via the VIPExchange Server behind F5, Kemp or NetScaler: health checks, SSL and bad-VIP errors 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domainProofpoint log (Exchange reply)Proofpoint with Exchange Server: connectors, TLS and the rejections admins see 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domainGateway delivery log (Exchange reply)Email gateway in front of Exchange Server: connectors, InternalSMTPServers and loops 550 Anti-Spoofing policy - Inbound not allowedNDR (app or device sending as your domain)Mimecast with Exchange Server: 451 Open relay not allowed, connectors and rejection codes 550 Invalid RecipientSender's NDR (mail to your domain)Mimecast with Exchange Server: 451 Open relay not allowed, connectors and rejection codes 550 permanent failure for one or more recipients (user@contoso.com:blocked)Sender's NDR (Barracuda rejection)Barracuda Email Protection with Exchange Server: connectors, smart host and 550 rejections 550 Submitter failed to authenticateNDR / Get-Queue LastErrorMimecast with Exchange Server: 451 Open relay not allowed, connectors and rejection codes 553 This route requires encryption (TLS)NDR / SMTP send protocol logMimecast with Exchange Server: 451 Open relay not allowed, connectors and rejection codes 553 This route requires TLS version 1.2 or greaterNDR / SMTP send protocol logMimecast with Exchange Server: 451 Open relay not allowed, connectors and rejection codes 554 5.4.6 Hop count exceeded - possible mail loopNDREmail signatures on Exchange Server (Exclaimer, CodeTwo): routing, duplicates and NDRs 554 5.4.6 Hop count exceeded - possible mail loopNDRSymantec DLP Network Prevent for Email with Exchange Server: modes, loops and queue errors 554 5.4.6 Hop count exceeded - possible mail loopNDRDLP and encryption gateways for Exchange Server (Forcepoint, Trellix): routing and loops 554 5.4.6 Hop count exceeded - possible mail loopNDREmail gateway in front of Exchange Server: connectors, InternalSMTPServers and loops 554 Mail loop detectedNDRMimecast with Exchange Server: 451 Open relay not allowed, connectors and rejection codes 554 Service unavailable; client host [IP or hostname] blocked using Barracuda ReputationSender's NDR (Barracuda ESG rejection)Barracuda Email Protection with Exchange Server: connectors, smart host and 550 rejections <user@example.com>... User unknownFortiMail log (recipient verification)FortiMail with Exchange Server: 550 5.7.1 Relay access denied, 451 and recipient checks A VSS critical writer has failed. Writer name: [Microsoft Exchange Writer].Veeam job logVeeam Backup & Replication with Exchange Server: VSS writer errors and logs not truncating Cannot notify writers about the 'BACKUP FINISH' event.Veeam job log (reported by admins)Veeam Backup & Replication with Exchange Server: VSS writer errors and logs not truncating Completed w/ one or more errorsCommvault Job HistoryNetBackup and Commvault with Exchange DAGs: passive copies, status 156 and VSS errors Error Code [80:36]: No more allocated streams are available.Commvault job detailsNetBackup and Commvault with Exchange DAGs: passive copies, status 156 and VSS errors Error Code [82:128] Network receive failedCommvault job detailsNetBackup and Commvault with Exchange DAGs: passive copies, status 156 and VSS errors ErrorImpersonateUserDenied: The account does not have permission to impersonate the requested user.EWS response (restore to mailbox)Veeam Explorer for Microsoft Exchange: ese.dll, Dirty Shutdown and permission errors Event ID 1052 (MSExchange Extensibility)Application logThird-party transport agents breaking Exchange mail flow (Trend Micro, ESET, Kaspersky) Event ID 3305 (Enterprise Vault)Event Viewer (Enterprise Vault log)Enterprise Vault and Exchange Server: event 3305, archiving tasks, throttling, shortcuts Event ID 16023 (MSExchange Extensibility)Application logThird-party transport agents breaking Exchange mail flow (Trend Micro, ESET, Kaspersky) Failed to acquire a use licenseTest-IRMConfigurationExchange Server IRM with the RMS connector: fixing Test-IRMConfiguration failures Failed to connect. Winsock error code: 10060, Win32 error code: 10060.Get-Queue LastError (to Barracuda)Barracuda Email Protection with Exchange Server: connectors, smart host and 550 rejections Failed to connect. Winsock error code: 10060, Win32 error code: 10060.Get-Queue LastErrorSymantec DLP Network Prevent for Email with Exchange Server: modes, loops and queue errors Faulting application name: EdgeTransport.exe ... Faulting module name: <third-party agent DLL>Application log (Event ID 1000)Third-party transport agents breaking Exchange mail flow (Trend Micro, ESET, Kaspersky) Final error: 0xe000fed1 - A failure occurred querying the Writer status.Backup Exec job log (reported by admins)Veritas Backup Exec and Exchange Server: 0xE000FED1 writer errors, GRT and DAG backups HTTP Error 503. The service is unavailable.Browser (OWA / ECP)Exchange Server behind F5, Kemp or NetScaler: health checks, SSL and bad-VIP errors JET_errDatabaseDirtyShutdown (-550)ESE-based tools / eseutilVeeam Explorer for Microsoft Exchange: ese.dll, Dirty Shutdown and permission errors Last error: Non-retryable errorvssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups Last error: Retryable errorvssadmin list writers (Exchange Writer)Veritas Backup Exec and Exchange Server: 0xE000FED1 writer errors, GRT and DAG backups Last error: Retryable errorvssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups Last error: The VSS Writer failed, but the operation can be retried (0x800423f3)Backup Exec job log (reported by admins)Veritas Backup Exec and Exchange Server: 0xE000FED1 writer errors, GRT and DAG backups Last error: The VSS Writer timed out (0x800423f2)Backup Exec job log (reported by admins)Veritas Backup Exec and Exchange Server: 0xE000FED1 writer errors, GRT and DAG backups Last error: Timed outvssadmin list writers (Exchange Writer)NetBackup and Commvault with Exchange DAGs: passive copies, status 156 and VSS errors Last error: Timed outvssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups Milter (fas_milter): timeout before data readFortiMail event logFortiMail with Exchange Server: 550 5.7.1 Relay access denied, 451 and recipient checks NetBackup status code: 156NetBackup job status / Activity MonitorNetBackup and Commvault with Exchange DAGs: passive copies, status 156 and VSS errors Recipient address rejected: User email address is marked as invalidSender's NDR (Proofpoint Essentials)Proofpoint with Exchange Server: connectors, TLS and the rejections admins see Snapshot technology error (0xE000FED1): A failure occurred querying the Writer status.Backup Exec job log (reported by admins)Veritas Backup Exec and Exchange Server: 0xE000FED1 writer errors, GRT and DAG backups State: [5] Waiting for completionvssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups State: [9] Failedvssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups State: Dirty Shutdowneseutil /mh (restored database copy)Veeam Explorer for Microsoft Exchange: ese.dll, Dirty Shutdown and permission errors Status for writer Microsoft Exchange Writer: STABLE (0x800423f3 - VSS_E_WRITERERROR_RETRYABLE)BETESTMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups System is rate limiting Envelope Sender <sender> due to high volume of messagesCisco gateway alertCisco Secure Email Gateway (IronPort) with Exchange Server: HAT, RAT and SMTP errors The attempt to discover the location of the administration service and organization failed.RMS connector setup wizardExchange Server IRM with the RMS connector: fixing Test-IRMConfiguration failures The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.OutlookExchange Server behind F5, Kemp or NetScaler: health checks, SSL and bad-VIP errors The execution time of agent '<agent name>' exceeded <n> milliseconds while handling event '<event>'Application log (Event ID 1050)Email signatures on Exchange Server (Exclaimer, CodeTwo): routing, duplicates and NDRs The execution time of agent '<agent name>' exceeded <n> milliseconds while handling event '<event>'Application log (MSExchange Extensibility 1050)Third-party transport agents breaking Exchange mail flow (Trend Micro, ESET, Kaspersky) The execution time of agent 'ScanMail Routing Agent' exceeded X milliseconds while handling event 'OnResolvedMessage'Application log (MSExchange Extensibility 1050)Third-party transport agents breaking Exchange mail flow (Trend Micro, ESET, Kaspersky) The Kerberos client received a KRB_AP_ERR_MODIFIED error from the serverSystem log (Event ID 4)Exchange Server behind F5, Kemp or NetScaler: health checks, SSL and bad-VIP errors The log copier was unable to communicate with serverApplication log (MSExchangeRepl event 2153)Microsoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups The Microsoft Exchange Transport service terminated unexpectedly.System log (Service Control Manager)Third-party transport agents breaking Exchange mail flow (Trend Micro, ESET, Kaspersky) This message was rejected by its destination for reasons outside the control of Proofpoint EssentialsProofpoint Essentials logProofpoint with Exchange Server: connectors, TLS and the rejections admins see Unfreeze error:[Backup job failed] Cannot create shadow copy of the volumes containing writer's dataVeeam job logVeeam Backup & Replication with Exchange Server: VSS writer errors and logs not truncating Verify <user@example.com> Failed, return TEMPFAILFortiMail antispam logFortiMail with Exchange Server: 550 5.7.1 Relay access denied, 451 and recipient checks VSSControl: Failed to freeze guest, wait timeoutVeeam job logVeeam Backup & Replication with Exchange Server: VSS writer errors and logs not truncating Writer's state: [VSS_WS_FAILED_AT_BACKUP_COMPLETE]. Error code: [0x800423f3].Veeam job log (reported by admins)Veeam Backup & Replication with Exchange Server: VSS writer errors and logs not truncating Writer's state: [VSS_WS_FAILED_AT_FREEZE]. Error code: [0x800423f2].Veeam job logVeeam Backup & Replication with Exchange Server: VSS writer errors and logs not truncating

NDR & SMTP status codes

Every code in the quick reference “Exchange Server NDR and SMTP status codes: a quick reference with causes and fixes”: what it means, the usual cause and the first check. Open the quick reference

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4.3.1 Insufficient system resourcesNDR / queue LastError452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed 4.3.2 Service not available / Service not activeNDR / queue LastErrorExchange components stuck Inactive after an update: ServerWideOffline and requesters 4.4.0 DNS query failedQueue LastError451 4.4.0 DNS query failed: fixing Exchange queues stuck in Retry 4.4.1 Connection timed outNDR / queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues 4.4.2 Connection droppedNDR / queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues 4.4.7 Message delayed / Queue expired; message expiredNDR / delay notification441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues 4.4.317 Cannot connect to remote server [Message=UntrustedRoot]NDR (Exchange Online / hybrid)Exchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.1.0 Sender deniedNDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found / User unknownNDR550 5.1.1 RESOLVER.ADR.ExRecipNotFound and IMCEAEX NDRs: fixing them with X500 addresses 5.1.3 STOREDRV.Submit; invalid recipient addressNDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.1.4 Recipient address reserved by RFC 2606SMTP session / NDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.1.5 Recipient address reserved by RFC 2606SMTP session / NDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.1.6 Recipient addresses in single label domains not acceptedSMTP session / NDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.1.7 Invalid address / Unknown sender addressNDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.1.8 Access denied, bad outbound senderNDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.1.10 Recipient not foundNDR (Exchange Online / hybrid)Remote mailboxes in Exchange hybrid: Enable-RemoteMailbox, attributes and common mistakes 5.2.1 Content Filter agent quarantined this messageNDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.2.2 Mailbox fullNDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.2.3 RESOLVER.RST.RecipSizeLimit; message too large for this recipientNDR550 5.3.4 ROUTING.SizeLimit and 5.2.3: every Exchange message size limit in one place 5.3.0 Too many related errorsNDRPoison message queue and a stuck Submission queue in Exchange: causes and safe fixes 5.3.2 STOREDRV.Deliver: Missing or bad StoreDriver MDB propertiesNDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.3.3 Unrecognized commandNDR / queue LastErrorExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.3.4 Message size exceeds fixed maximum message sizeNDR550 5.3.4 ROUTING.SizeLimit and 5.2.3: every Exchange message size limit in one place 5.3.5 System incorrectly configuredNDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.3.190 Journaling on-premises messages to Microsoft 365 or Office 365 not supported when Journaling Archive is disabledNDR (Exchange Online / hybrid)Exchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.4.1 Recipient address rejected: Access denied / Relay Access DeniedNDR (Exchange Online / hybrid)NDR 550 5.4.1 “Recipient address rejected: Access denied”: Directory-Based Edge Blocking 5.4.4 SMTPSEND.DNS.NonExistentDomain; nonexistent domainNDR / queue LastError451 4.4.0 DNS query failed: fixing Exchange queues stuck in Retry 5.4.6 Hop count exceeded - possible mail loopNDR554 5.4.6 and 5.4.14 Hop count exceeded: finding and fixing Exchange mail loops 5.4.14 Routing loop detectedNDR (Exchange Online / hybrid)554 5.4.6 and 5.4.14 Hop count exceeded: finding and fixing Exchange mail loops 5.5.2 Send hello firstSMTP sessionExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.5.3 Too many recipientsNDR / SMTP sessionExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.7.1 Client was not authenticatedSMTP session / NDR530 5.7.1 Client was not authenticated: fixing anonymous SMTP submission to Exchange 5.7.1 Delivery not authorized, message refusedNDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.7.1 Unable to relaySMTP session / NDR550 5.7.54 Unable to relay: configuring anonymous relay on Exchange Server safely 5.7.3 Cannot achieve Exchange Server authentication / Not AuthorizedNDR / queue LastErrorExchange Server NDR and SMTP status codes: a quick reference with causes and fixes 5.7.54 Unable to relay recipient in non-accepted domainSMTP session / NDR550 5.7.54 Unable to relay: configuring anonymous relay on Exchange Server safely 5.7.64 TenantAttribution; Relay Access DeniedNDR (Exchange Online / hybrid)Exchange hybrid mail flow: connectors, TLS certificates and centralized mail transport 5.7.900-5.7.999 Delivery not authorized, message refusedNDRExchange Server NDR and SMTP status codes: a quick reference with causes and fixes

Queue LastError messages

Every code in the quick reference “Exchange Server queue LastError messages: a quick reference for stuck queues”: what it means, the usual cause and the first check. Open the quick reference

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421 4.3.2 The maximum number of concurrent server connections has exceeded a per-source limit, closing transmission channelGet-Queue LastError (remote reply)Email gateway in front of Exchange Server: connectors, InternalSMTPServers and loops 421 Exceeded allowable connection time, disconnecting.Get-Queue LastError (Cisco reply)Cisco Secure Email Gateway (IronPort) with Exchange Server: HAT, RAT and SMTP errors 421 Timed out waiting for successful message injection, disconnecting.Get-Queue LastError (Cisco reply)Cisco Secure Email Gateway (IronPort) with Exchange Server: HAT, RAT and SMTP errors 441 4.4.1 Error encountered while communicating with primary target IP address: the connection to the next hop failedGet-Queue LastError / Queue Viewer441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues 451 4.4.0 Error encountered while communicating with primary target IP address: "421 4.4.2 Connection dropped due to SocketError."Get-Queue LastErrorSMTP protocol logging on Exchange: reading send and receive logs to debug connections 451 4.4.0 Primary target IP address responded with: "421 4.4.1 Connection timed out."Get-Queue LastError / Queue ViewerSMTP protocol logging on Exchange: reading send and receive logs to debug connections 451 4.4.0 Primary target IP address responded with: "454 4.7.0 Temporary authentication failure."Get-Queue LastError / Queue ViewerExchange Server queue LastError messages: a quick reference for stuck queues Attempted failover to alternate host, but that did not succeed.Get-Queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues DeliveryType: DnsConnectorDelivery in Retry: MX-based delivery to an external domain failingGet-Queue / Queue Viewer451 4.4.0 DNS query failed: fixing Exchange queues stuck in Retry DeliveryType: SmartHostConnectorDelivery in Retry: the smart host isn't accepting mailGet-Queue / Queue Viewer441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues DeliveryType: SmtpDeliveryToMailbox growing: delivery to a mailbox database is stalledGet-Queue / Queue ViewerExchange Server queue LastError messages: a quick reference for stuck queues DeliveryType: SmtpRelayToConnectorSourceServers in Retry: the connector's source server isn't reachableGet-Queue / Queue ViewerExchange Server queue LastError messages: a quick reference for stuck queues DeliveryType: SmtpRelayToDag / SmtpRelayToRemoteActiveDirectorySite in Retry: internal hop failingGet-Queue / Queue ViewerExchange Server queue LastError messages: a quick reference for stuck queues DeliveryType: SmtpRelayToServers in Retry: the distribution group's expansion server isn't reachableGet-Queue / Queue ViewerExchange Server queue LastError messages: a quick reference for stuck queues DeliveryType: SmtpRelayWithinAdSiteToEdge in Retry: the Edge Transport server isn't reachableGet-Queue / Queue ViewerEdgeSync failing with "The LDAP server is unavailable": re-creating the Edge Subscription DNS query failed with error InfoNoRecordsGet-Queue LastError451 4.4.0 DNS query failed: fixing Exchange queues stuck in Retry Either there are no alternate hosts, or delivery failed to all alternate hosts.Get-Queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues Event ID 1035 (MSExchangeTransport): Inbound authentication failed with error IllegalMessage for Receive connectorApplication log (receiving server)Exchange Server queue LastError messages: a quick reference for stuck queues Failed to connect. Winsock error code: 10060, Win32 error code: 10060.Get-Queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues Message Status: PendingRemove / PendingSuspend: removed or suspended during transmissionGet-Message / Queue ViewerExchange Server queue LastError messages: a quick reference for stuck queues Poison message queue (NextHopDomain: Poison Message): messages isolated after a crashGet-Queue / Queue ViewerPoison message queue and a stuck Submission queue in Exchange: causes and safe fixes Shadow queue growing (DeliveryType: ShadowRedundancy): redundant copies not releasedGet-Queue / Queue ViewerExchange Server queue LastError messages: a quick reference for stuck queues Status: Connecting that doesn't clear: the queue can't finish connecting to the next hopGet-Queue / Queue ViewerExchange Server queue LastError messages: a quick reference for stuck queues Status: Retry: the last connection attempt failed and the queue is waiting to retryGet-Queue / Queue Viewer441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues Status: Suspended: an administrator suspended the queueGet-Queue / Queue ViewerExchange Server queue LastError messages: a quick reference for stuck queues Submission queue growing (NextHopDomain: Submission): messages waiting for the categorizerGet-Queue / Queue ViewerPoison message queue and a stuck Submission queue in Exchange: causes and safe fixes Unreachable queue (NextHopDomain: Unreachable Domain): messages that can't be routedGet-Queue / Queue ViewerExchange Server queue LastError messages: a quick reference for stuck queues Velocity below 0 with a growing MessageCount: the queue isn't drainingGet-QueueExchange Server queue LastError messages: a quick reference for stuck queues Winsock error code: 10013 WSAEACCES: permission denied, socket access forbiddenGet-Queue LastError (Failed to connect)Exchange Server queue LastError messages: a quick reference for stuck queues Winsock error code: 10050 WSAENETDOWN: network is downGet-Queue LastError (Failed to connect)Exchange Server queue LastError messages: a quick reference for stuck queues Winsock error code: 10051 WSAENETUNREACH: network is unreachableGet-Queue LastError (Failed to connect)Exchange Server queue LastError messages: a quick reference for stuck queues Winsock error code: 10053 WSAECONNABORTED: software caused connection abort on the local hostGet-Queue LastError (Failed to connect)Exchange Server queue LastError messages: a quick reference for stuck queues Winsock error code: 10054 WSAECONNRESET: connection reset by peer (forcibly closed by the remote host)Get-Queue LastError (Failed to connect)SMTP protocol logging on Exchange: reading send and receive logs to debug connections Winsock error code: 10061 WSAECONNREFUSED: the target computer actively refused the connectionGet-Queue LastError (Failed to connect)441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues Winsock error code: 10065 WSAEHOSTUNREACH: no route to hostGet-Queue LastError (Failed to connect)Exchange Server queue LastError messages: a quick reference for stuck queues

ESE database error codes

Every code in the quick reference “Exchange database (ESE/JET) error codes: a quick reference with meanings and first fixes”: what it means, the usual cause and the first check. Open the quick reference

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-501 JET_errLogFileCorrupt: a transaction log file is corrupteseutil / Application log (ESE)Exchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery -509 JET_errMissingPreviousLogFile: the log file the checkpoint points to is missingeseutil /r / Mount-DatabaseExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -510 JET_errLogWriteFail: writing to the log file failedApplication log (ESE)Exchange transaction logs filling the disk: backups, circular logging and safe recovery -513 JET_errLogGenerationMismatch: a log's file name doesn't match its internal generationeseutil /rExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -514 JET_errBadLogVersion: the log version isn't compatible with this ESE versioneseutil /rExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -515 JET_errInvalidLogSequence: the next log's timestamp doesn't match the expected oneeseutil /r / Mount-DatabaseExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -526 JET_errInvalidBackup: incremental backup refused: circular logging is enabledBackup job log / Application logExchange transaction logs filling the disk: backups, circular logging and safe recovery -528 JET_errMissingLogFile: the current log file (for example E00.log) is missingMount-Database (ec=-528) / eseutilExchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery -529 JET_errLogDiskFull: the log disk is fullApplication log (ESE)Exchange transaction logs filling the disk: backups, circular logging and safe recovery -530 JET_errBadLogSignature: a log file has a bad signatureeseutil /rExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -533 JET_errCheckpointCorrupt: the checkpoint file is missing or corrupteseutil /r / Mount-DatabaseExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -539 JET_errDatabaseLogSetMismatch: the database doesn't belong with this set of log fileseseutil /r / Mount-DatabaseExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -543 JET_errRequiredLogFilesMissing: log files required for recovery are missingeseutil /r / Mount-DatabaseExchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery -546 JET_errLogSectorSizeMismatch: log sector size doesn't match the volume's sector sizeeseutil /r / Mount-DatabaseExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -550 JET_errDatabaseDirtyShutdown: database not shut down cleanly; recovery must run firstMount-Database / eseutilExchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery -560 JET_errMissingFullBackup: incremental attempted without a previous full backupBackup job log / Application logExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -612 JET_errLogReadVerifyFailure: checksum error in a log file during backupBackup job log / Application logExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -614 JET_errCheckpointDepthTooDeep: too many log generations between the checkpoint and the current logApplication log (ESE)Exchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1008 JET_errDatabaseFileReadOnly: a read-only database file was opened for read/writeeseutil / Mount-DatabaseExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1018 JET_errReadVerifyFailure: page checksum mismatch on a database pageApplication log (ESE 474) / eseutilJET error -1018 and ESE event 474: page checksum corruption in an Exchange database -1019 JET_errPageNotInitialized: a database page that should hold data is blankApplication log (ESE 476)JET error -1018 and ESE event 474: page checksum corruption in an Exchange database -1022 JET_errDiskIO: Windows returned a disk I/O error for the fileMount-Database / Application logJET error -1018 and ESE event 474: page checksum corruption in an Exchange database -1032 JET_errFileAccessDenied: the file is locked or in useMount-Database / eseutilAntivirus on Exchange Server: the exclusions Microsoft documents and how to test them -1069 JET_errVersionStoreOutOfMemory: version store out of memory, even after cleanupApplication log (ESE)Exchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1090 JET_errInstanceUnavailable: the instance hit a fatal error and can't be usedApplication log (ESE)Exchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1092 JET_errInstanceUnavailableDueToFatalLogDiskFull: instance unusable after the log disk filled during a critical operationApplication log (ESE)Exchange transaction logs filling the disk: backups, circular logging and safe recovery -1119 JET_errReadLostFlushVerifyFailure: lost flush: an earlier write is missing from the page on diskApplication log (ESE)Exchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1206 JET_errDatabaseCorrupted: not a database file, or a corrupt databaseeseutil / Mount-DatabaseExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1209 JET_errInvalidDatabaseVersion: this ESE version is incompatible with the databaseeseutil / restore toolExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1213 JET_errPageSizeMismatch: the database page size doesn't match the engineeseutilExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1215 JET_errDatabaseSharingViolation: another database instance is using this databaseeseutilExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1216 JET_errAttachedDatabaseMismatch: the logs reference a database that is missing or doesn't matcheseutil /r / Mount-DatabaseExchange database won't mount: Dirty Shutdown, ec=1108, eseutil /mh and soft recovery -1220 JET_errCatalogCorrupted: corruption in the database catalog (its internal list of tables)eseutil / Application log (ESE)Exchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1414 JET_errSecondaryIndexCorrupted: a secondary index is corrupt; the database must be defragmentedApplication log (ESE)Exchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1526 JET_errLVCorrupted: corruption in a long-value tree (where large column values are stored)Application log (ESE) / move requestExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1808 JET_errDiskFull: no space left on the diskeseutil / Application log (ESE)Exchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -1811 JET_errFileNotFound: a file wasn't found at the path giveneseutil / Mount-DatabaseExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -2402 JET_errOSSnapshotTimeOut: the VSS shadow copy timed outBackup job log / Application logExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes -2403 JET_errOSSnapshotNotAllowed: shadow copy refused: a backup or recovery is already in progressBackup job log / Application logExchange database (ESE/JET) error codes: a quick reference with meanings and first fixes

TLS & certificate errors

Every code in the quick reference “TLS, Schannel and certificate errors on Exchange Server: a quick reference”: what it means, the usual cause and the first check. Open the quick reference

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0x800B010A CERT_E_CHAINING: A certificate chain could not be built to a trusted root authority.certutil -verify outputExchange Server certificates: renewing the SAN certificate and the Auth certificate 0x800B010F CERT_E_CN_NO_MATCH: The certificate's CN name does not match the passed value.certutil / error textOutlook “The name on the security certificate is invalid”: Exchange URLs vs SAN names 0x800B0101 CERT_E_EXPIRED: A required certificate is not within its validity periodcertutil -verify outputExchange Server certificates: renewing the SAN certificate and the Auth certificate 0x800B0109 CERT_E_UNTRUSTEDROOT: A certificate chain processed, but terminated in a root certificate which is not trustedcertutil -verify outputTLS, Schannel and certificate errors on Exchange Server: a quick reference 0x8009030D SEC_E_UNKNOWN_CREDENTIALS: The credentials supplied to the package were not recognizedSchannel 36870 / error textExchange Server certificates: renewing the SAN certificate and the Auth certificate 0x8009030E SEC_E_NO_CREDENTIALS: No credentials are available in the security packageSchannel events / error textEvent ID 12014: Exchange can't find a TLS certificate for a connector FQDN 0x8009310B CRYPT_E_ASN1_BADTAG: ASN1 bad tag value met.Certificate import error textTLS, Schannel and certificate errors on Exchange Server: a quick reference 0x80090016 NTE_BAD_KEYSET: Keyset does not existcertutil / error textExchange Server certificates: renewing the SAN certificate and the Auth certificate 0x80090302 SEC_E_UNSUPPORTED_FUNCTION: The function requested is not supportedSchannel events / error textTLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow 0x80090325 SEC_E_UNTRUSTED_ROOT: The certificate chain was issued by an authority that is not trusted.Schannel events / error textExchange Server certificates: renewing the SAN certificate and the Auth certificate 0x80090326 SEC_E_ILLEGAL_MESSAGE: The message received was unexpected or badly formatted.Schannel events / error textTLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow 0x80090327 SEC_E_CERT_UNKNOWN: An unknown error occurred while processing the certificate.Schannel events / error textTLS, Schannel and certificate errors on Exchange Server: a quick reference 0x80090328 SEC_E_CERT_EXPIRED: The received certificate has expired.Schannel events / error textExchange Server certificates: renewing the SAN certificate and the Auth certificate 0x80090331 SEC_E_ALGORITHM_MISMATCH: The client and server cannot communicate, because they do not possess a common algorithm.Error text (HCW, scripts, .NET apps)TLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow 0x80092010 CRYPT_E_REVOKED: The certificate is revoked.certutil -verify outputTLS, Schannel and certificate errors on Exchange Server: a quick reference 0x80092012 CRYPT_E_NO_REVOCATION_CHECK: The revocation function was unable to check revocation for the certificate.certutil -verify outputTLS, Schannel and certificate errors on Exchange Server: a quick reference 0x80092013 CRYPT_E_REVOCATION_OFFLINE: unable to check revocation because the revocation server was offlinecertutil -verify outputTLS, Schannel and certificate errors on Exchange Server: a quick reference Schannel 36869: the credential's certificate does not have a private key information property attachedSystem log (Schannel)Exchange Server certificates: renewing the SAN certificate and the Auth certificate Schannel 36870: A fatal error occurred when attempting to access the credential private keySystem log (Schannel)Exchange Server certificates: renewing the SAN certificate and the Auth certificate Schannel 36871: A fatal error occurred while creating a TLS credentialSystem log (Schannel)TLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow Schannel 36872 / 36886: No suitable default server credential exists on this systemSystem log (Schannel)TLS, Schannel and certificate errors on Exchange Server: a quick reference Schannel 36873: No supported cipher suites were found when initiating a connectionSystem log (Schannel)TLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow Schannel 36874: none of the cipher suites supported by the client application are supported by the serverSystem log (Schannel)TLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow Schannel 36876: The certificate received from the remote server has not validated correctlySystem log (Schannel)TLS, Schannel and certificate errors on Exchange Server: a quick reference Schannel 36877: The certificate received from the remote client application has not validated correctlySystem log (Schannel)TLS, Schannel and certificate errors on Exchange Server: a quick reference Schannel 36881: The certificate received from the remote server has expiredSystem log (Schannel)TLS, Schannel and certificate errors on Exchange Server: a quick reference Schannel 36882: The certificate received from the remote server was issued by an untrusted certification authoritySystem log (Schannel)TLS, Schannel and certificate errors on Exchange Server: a quick reference Schannel 36883: The certificate received from the remote server has been revokedSystem log (Schannel)TLS, Schannel and certificate errors on Exchange Server: a quick reference Schannel 36884: The certificate received from the remote server does not contain the expected nameSystem log (Schannel)Outlook “The name on the security certificate is invalid”: Exchange URLs vs SAN names Schannel 36887: A fatal alert was received from the remote endpoint (TLS alert code in the text)System log (Schannel)TLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow Schannel 36888: A fatal alert was generated and sent to the remote endpointSystem log (Schannel)TLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow Status: RevocationCheckFailureGet-ExchangeCertificateTLS, Schannel and certificate errors on Exchange Server: a quick reference The certificate status could not be determined because the revocation check failed.Exchange admin center (Certificates)TLS, Schannel and certificate errors on Exchange Server: a quick reference TLS alert 10 unexpected_message: an inappropriate message was received (SEC_E_ILLEGAL_MESSAGE)System log (Schannel 36887 / 36888)TLS, Schannel and certificate errors on Exchange Server: a quick reference TLS alert 20 bad_record_mac: a record failed its integrity check (SEC_E_MESSAGE_ALTERED)System log (Schannel 36887 / 36888)TLS, Schannel and certificate errors on Exchange Server: a quick reference TLS alert 40 handshake_failure: no acceptable set of security parameters (SEC_E_ILLEGAL_MESSAGE)System log (Schannel 36887 / 36888)TLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow TLS alert 42 bad_certificate: the certificate was corrupt or its signature invalid (SEC_E_CERT_UNKNOWN)System log (Schannel 36887 / 36888)TLS, Schannel and certificate errors on Exchange Server: a quick reference TLS alert 43 unsupported_certificate: certificate type not supported (SEC_E_CERT_UNKNOWN)System log (Schannel 36887 / 36888)TLS, Schannel and certificate errors on Exchange Server: a quick reference TLS alert 44 certificate_revoked: the certificate was revoked by its issuer (CRYPT_E_REVOKED)System log (Schannel 36887 / 36888)TLS, Schannel and certificate errors on Exchange Server: a quick reference TLS alert 45 certificate_expired: the certificate expired or isn't valid yet (SEC_E_CERT_EXPIRED)System log (Schannel 36887 / 36888)Exchange Server certificates: renewing the SAN certificate and the Auth certificate TLS alert 46 certificate_unknown: another certificate problem made it unacceptable (SEC_E_CERT_UNKNOWN)System log (Schannel 36887 / 36888)TLS, Schannel and certificate errors on Exchange Server: a quick reference TLS alert 48 unknown_ca: the issuing CA couldn't be found or trusted (SEC_E_UNTRUSTED_ROOT)System log (Schannel 36887 / 36888)Exchange Server certificates: renewing the SAN certificate and the Auth certificate TLS alert 49 access_denied: valid certificate, but access control refused it (SEC_E_LOGON_DENIED)System log (Schannel 36887 / 36888)TLS, Schannel and certificate errors on Exchange Server: a quick reference TLS alert 50 decode_error: a message couldn't be decoded (SEC_E_ILLEGAL_MESSAGE)System log (Schannel 36887 / 36888)TLS, Schannel and certificate errors on Exchange Server: a quick reference TLS alert 51 decrypt_error: a handshake cryptographic operation failed (SEC_E_DECRYPT_FAILURE)System log (Schannel 36887 / 36888)TLS, Schannel and certificate errors on Exchange Server: a quick reference TLS alert 70 protocol_version: the offered protocol version isn't supported (SEC_E_UNSUPPORTED_FUNCTION)System log (Schannel 36887 / 36888)TLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow TLS alert 71 insufficient_security: stronger ciphers required than offered (SEC_E_ALGORITHM_MISMATCH)System log (Schannel 36887 / 36888)TLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow TLS alert 80 internal_error: an internal error unrelated to the peer (SEC_E_INTERNAL_ERROR)System log (Schannel 36887 / 36888)TLS, Schannel and certificate errors on Exchange Server: a quick reference TLS alert 90 user_canceled: the handshake was canceled (SEC_E_UNFINISHED_CONTEXT_DELETED)System log (Schannel 36887 / 36888)TLS, Schannel and certificate errors on Exchange Server: a quick reference

ActiveSync status codes

Every code in the quick reference “Exchange ActiveSync status codes: a quick reference for mobile sync errors”: what it means, the usual cause and the first check. Open the quick reference

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101 / 102 / 103 InvalidContent / InvalidWBXML / InvalidXML: the request body is invalidActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 108 / 109 DeviceIdMissingOrInvalid / DeviceTypeMissingOrInvalid: missing or badly formatted device ID or typeActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 110 ServerError: unknown server error, the device should not retryActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 111 ServerErrorRetryLater: unknown server error, the device should retry laterActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 112 ActiveDirectoryAccessDenied: the server can't read or write an object in the directory serviceActiveSync mailbox log (Status)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 113 MailboxQuotaExceeded: the mailbox has reached its size quotaActiveSync mailbox log (Status)Mailbox full in Exchange Server: quotas, ProhibitSendQuota and the 554 5.2.2 NDR 114 MailboxServerOffline: the mailbox server is offlineActiveSync mailbox log (Status)Exchange components stuck Inactive after an update: ServerWideOffline and requesters 115 SendQuotaExceeded: the request would exceed the send quotaActiveSync mailbox log (Status)Mailbox full in Exchange Server: quotas, ProhibitSendQuota and the 554 5.2.2 NDR 116 MessageRecipientUnresolved: a recipient could not be resolved to an email addressActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 118 MessagePreviouslySent: the message was already sent in a previous requestActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 119 / 183 MessageHasNoRecipient / InvalidRecipients: no recipient or an invalid SMTP addressActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 120 MailSubmissionFailed: the server failed to submit the message for deliveryActiveSync mailbox log (Status)452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed 122 AttachmentIsTooLarge: the attachment is too large to be processed by this requestActiveSync mailbox log (Status)550 5.3.4 ROUTING.SizeLimit and 5.2.3: every Exchange message size limit in one place 123 UserHasNoMailbox: a mailbox could not be found for the userActiveSync mailbox log (Status)ActiveSync device access in Exchange Online: quarantine, access rules and blocked devices 124 UserCannotBeAnonymous: the request was sent without credentialsActiveSync mailbox log (Status)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 125 UserPrincipalCouldNotBeFound: the user was not found in the directory serviceActiveSync mailbox log (Status)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 126 UserDisabledForSync: the user is not allowed to use ActiveSyncActiveSync mailbox log (Status)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 129 DeviceIsBlockedForThisUser: the user may sync only some devices and this isn't one of themActiveSync mailbox log (Status)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 130 AccessDenied: the user is not allowed to perform that requestActiveSync mailbox log (Status)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 131 AccountDisabled: the user's account is disabledActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 132 SyncStateNotFound: the device's sync state file is missingActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 133 SyncStateLocked: the sync state is locked, possibly by a mailbox moveActiveSync mailbox log (Status)StalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves 134 / 136 SyncStateCorrupt / SyncStateVersionInvalid: the device's sync state is corrupt or invalidActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 137 / 138 CommandNotSupported / VersionNotSupported: command or protocol version not supportedActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 139 / 141 DeviceNotFullyProvisionable / LegacyDeviceOnStrictPolicy: the device can't apply the policyActiveSync mailbox log (Status)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 140 RemoteWipeRequested: a remote wipe is pending for the deviceActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 142 DeviceNotProvisioned: a policy is in place and the device must provision firstActiveSync mailbox log (Status)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 143 / 144 PolicyRefresh / InvalidPolicyKey: the device must provision againActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 145 ExternallyManagedDevicesNotAllowed: externally managed devices are not allowed to syncActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 148 RemoteServerHasNoSSL: the request must be proxied to a server without SSL enabledActiveSync mailbox log (Status)Exchange virtual directories: setting the URLs and resetting a broken one 150 ItemNotFound: the item in a SmartReply or SmartForward request wasn't foundActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 151 TooManyFolders: the mailbox contains too many folders (1,000 by default)ActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 160 / 161 AvailabilityTooManyRecipients / AvailabilityDLLimitReached: free/busy request too largeActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors 162 / 163 AvailabilityTransientFailure / AvailabilityFailure: the availability request failedActiveSync mailbox log (Status)Hybrid free/busy not working: OAuth, the dedicated hybrid app and Test-OAuthConnectivity 168 IRM_FeatureDisabled: the Information Rights Management feature is disabledActiveSync mailbox log (Status)Exchange Server IRM with the RMS connector: fixing Test-IRMConfiguration failures 169 / 170 IRM_TransientError / IRM_PermanentError: Information Rights Management encountered an errorActiveSync mailbox log (Status)Exchange Server IRM with the RMS connector: fixing Test-IRMConfiguration failures 177 MaximumDevicesReached: the account has too many device partnershipsActiveSync mailbox log (Status)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors 184 OneOrMoreExceptionsFailed: not all exceptions of a calendar series were savedActiveSync mailbox log (Status)Exchange ActiveSync status codes: a quick reference for mobile sync errors FolderSync status 6 / 11: An error occurred on the server / An unknown error occurredActiveSync mailbox log (FolderSync)Exchange ActiveSync status codes: a quick reference for mobile sync errors FolderSync status 9: Synchronization key mismatch or invalid synchronization keyActiveSync mailbox log (FolderSync)Exchange ActiveSync status codes: a quick reference for mobile sync errors HTTP 400 Bad Request: malformed request (older protocol versions)IIS log (Microsoft-Server-ActiveSync)Exchange ActiveSync status codes: a quick reference for mobile sync errors HTTP 401 Unauthorized: credentials rejectedIIS log (Microsoft-Server-ActiveSync)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors HTTP 403 Forbidden: user not enabled for ActiveSync, not found, or directory access deniedIIS log (Microsoft-Server-ActiveSync)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors HTTP 449: the device must provision (apply the mailbox policy) before it can syncIIS log (Microsoft-Server-ActiveSync)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors HTTP 451 Redirect: the mailbox is served elsewhereIIS log (Microsoft-Server-ActiveSync)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors HTTP 500 Internal Server Error: server-side failure (older protocol versions)IIS log (Microsoft-Server-ActiveSync)ActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors HTTP 503 Service Unavailable: server or component unavailable, retry laterIIS log (Microsoft-Server-ActiveSync)Exchange Server behind F5, Kemp or NetScaler: health checks, SSL and bad-VIP errors HTTP 507: mailbox quota exceeded (older protocol versions)IIS log (Microsoft-Server-ActiveSync)Mailbox full in Exchange Server: quotas, ProhibitSendQuota and the 554 5.2.2 NDR Ping status 7: Folder hierarchy sync requiredActiveSync mailbox log (Ping response)Exchange ActiveSync status codes: a quick reference for mobile sync errors Sync status 3: Invalid synchronization keyActiveSync mailbox log (Sync response)Exchange ActiveSync status codes: a quick reference for mobile sync errors Sync status 5: Server errorActiveSync mailbox log (Sync response)Exchange ActiveSync status codes: a quick reference for mobile sync errors Sync status 8: Object not foundActiveSync mailbox log (Sync response)Exchange ActiveSync status codes: a quick reference for mobile sync errors Sync status 9: The Sync command cannot be completed (account could be out of disk space)ActiveSync mailbox log (Sync response)Mailbox full in Exchange Server: quotas, ProhibitSendQuota and the 554 5.2.2 NDR Sync status 12: The folder hierarchy has changedActiveSync mailbox log (Sync response)Exchange ActiveSync status codes: a quick reference for mobile sync errors Sync status 14: Invalid Wait or HeartbeatInterval valueActiveSync mailbox log (Sync response)Exchange ActiveSync status codes: a quick reference for mobile sync errors Sync status 16: Retry (a retriable server error)ActiveSync mailbox log (Sync response)Exchange ActiveSync status codes: a quick reference for mobile sync errors

Outlook & Autodiscover error codes

Every code in the quick reference “Outlook, Autodiscover and OAB error codes with Exchange Server: a quick reference”: what it means, the usual cause and the first check. Open the quick reference

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0x800CCC0E Cannot connect to the server.Outlook (POP3/IMAP4 account)POP3 and IMAP4 on Exchange Server: fixing NO LOGIN failed, missing banners and TLS errors 0x800CCC0F The connection to the server was interrupted.Outlook (POP3/IMAP4 account)POP3 and IMAP4 on Exchange Server: fixing NO LOGIN failed, missing banners and TLS errors 0x801901F7 BG_E_HTTP_ERROR_503: the service is temporarily overloadedOutlook (Download Address Book)Exchange Server behind F5, Kemp or NetScaler: health checks, SSL and bad-VIP errors 0x801901F8 BG_E_HTTP_ERROR_504: timed out waiting for a gatewayOutlook (Download Address Book)Exchange Server behind F5, Kemp or NetScaler: health checks, SSL and bad-VIP errors 0x8004010D MAPI_E_NOT_ENOUGH_DISK: not enough disk space to complete the operationOutlook Send/ReceiveOutlook, Autodiscover and OAB error codes with Exchange Server: a quick reference 0x8004010F MAPI_E_NOT_FOUND: object not found (The operation failed. An object could not be found.)Outlook (Download Address Book)Offline address book not downloading in Outlook: fixing 0x8004010F and 0x80190194 0x8004011B MAPI_E_CORRUPT_DATA: internal inconsistency in a database or property valueOutlook Send/ReceiveNew-MailboxRepairRequest: fixing logical corruption in Exchange mailboxes 0x8004011D The server is not available. Contact your administrator if this condition persists.Outlook Send/Receive"The connection to Microsoft Exchange is unavailable": fixing Outlook on Exchange Server 0x80004005 E_FAIL / MAPI_E_CALL_FAILED: the operation failed for an unspecified reasonOutlook Send/ReceiveOutlook, Autodiscover and OAB error codes with Exchange Server: a quick reference 0x80040110 MAPI_E_VERSION: client and server versions are not compatibleOutlookOutlook, Autodiscover and OAB error codes with Exchange Server: a quick reference 0x80040111 MAPI_E_LOGON_FAILED: the client was unable to log on to the serverOutlookOutlook keeps prompting for a password with Exchange Server: the usual causes and fixes 0x80040112 MAPI_E_SESSION_LIMIT: unable to create any more sessionsOutlookOutlook, Autodiscover and OAB error codes with Exchange Server: a quick reference 0x80040115 MAPI_E_NETWORK_ERROR: a problem with network operations or servicesOutlook Send/Receive"The connection to Microsoft Exchange is unavailable": fixing Outlook on Exchange Server 0x80040123 ecTimeSkew (MAPI_E_INVALID_ACCESS_TIME): clock skew between serversOutlookOutlook, Autodiscover and OAB error codes with Exchange Server: a quick reference 0x80040200 MAPI_E_END_OF_SESSION: the server session was destroyed, possibly by a restartOutlookOutlook, Autodiscover and OAB error codes with Exchange Server: a quick reference 0x80040700 MAPI_E_AMBIGUOUS_RECIP: a recipient matches more than one directory entryOutlook (Check Names / send)Outlook, Autodiscover and OAB error codes with Exchange Server: a quick reference 0x80040900 MAPI_E_NAMED_PROP_QUOTA_EXCEEDED: no more named property mappingsOutlook / Application logOutlook, Autodiscover and OAB error codes with Exchange Server: a quick reference 0x80070005 E_ACCESSDENIED / MAPI_E_NO_ACCESS: insufficient access rightsOutlook Send/ReceiveOutlook, Autodiscover and OAB error codes with Exchange Server: a quick reference 0x80190191 BG_E_HTTP_ERROR_401: the OAB download requires user authenticationOutlook (Download Address Book)Offline address book not downloading in Outlook: fixing 0x8004010F and 0x80190194 0x80190194 BG_E_HTTP_ERROR_404: the OAB download URL does not exist on the serverOutlook (Download Address Book)Offline address book not downloading in Outlook: fixing 0x8004010F and 0x80190194 0x80190197 BG_E_HTTP_ERROR_407: the proxy requires user authenticationOutlook (Download Address Book)Outlook, Autodiscover and OAB error codes with Exchange Server: a quick reference 600 Invalid Request (Autodiscover XML error response)Browser (autodiscover.xml)Outlook, Autodiscover and OAB error codes with Exchange Server: a quick reference Allow this website to configure <address> server settings?Outlook (account setup)Outlook, Autodiscover and OAB error codes with Exchange Server: a quick reference Autoconfiguration was unable to determine your settings!Test E-mail AutoConfigurationAutodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors Autodiscover to https://autodiscover.contoso.com/autodiscover/autodiscover.xml Failed (0x800C8203)Test E-mail AutoConfiguration (Log)Autodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened.Outlook (start-up)Outlook, Autodiscover and OAB error codes with Exchange Server: a quick reference GetLastError=12002 ERROR_INTERNET_TIMEOUT: the request has timed outTest E-mail AutoConfiguration (Log)Outlook, Autodiscover and OAB error codes with Exchange Server: a quick reference GetLastError=12007 ERROR_INTERNET_NAME_NOT_RESOLVED: the server name could not be resolvedTest E-mail AutoConfiguration (Log)Autodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors GetLastError=12029 ERROR_INTERNET_CANNOT_CONNECT: the attempt to connect to the server failedTest E-mail AutoConfiguration (Log)Autodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors GetLastError=12030 ERROR_INTERNET_CONNECTION_ABORTED: the connection with the server was terminatedTest E-mail AutoConfiguration (Log)Exchange Server behind F5, Kemp or NetScaler: health checks, SSL and bad-VIP errors GetLastError=12037 ERROR_INTERNET_SEC_CERT_DATE_INVALID: the certificate is expiredTest E-mail AutoConfiguration (Log)Exchange Server certificates: renewing the SAN certificate and the Auth certificate GetLastError=12038 ERROR_INTERNET_SEC_CERT_CN_INVALID: certificate host name is incorrectTest E-mail AutoConfiguration (Log)Outlook “The name on the security certificate is invalid”: Exchange URLs vs SAN names GetLastError=12044 ERROR_INTERNET_CLIENT_AUTH_CERT_NEEDED: the server requests client authenticationTest E-mail AutoConfiguration (Log)Outlook, Autodiscover and OAB error codes with Exchange Server: a quick reference GetLastError=12045 ERROR_INTERNET_INVALID_CA: unfamiliar certificate authorityTest E-mail AutoConfiguration (Log)Outlook, Autodiscover and OAB error codes with Exchange Server: a quick reference GetLastError=12057 ERROR_INTERNET_SEC_CERT_REV_FAILED: certificate revocation check failedTest E-mail AutoConfiguration (Log)Outlook, Autodiscover and OAB error codes with Exchange Server: a quick reference GetLastError=12157 ERROR_INTERNET_SECURITY_CHANNEL_ERROR: internal error loading the SSL librariesTest E-mail AutoConfiguration (Log)TLS hardening on Exchange Server: TLS 1.2, TLS 1.3 and ciphers without breaking mail flow HTTP 401 Unauthorized on /Autodiscover, /mapi/emsmdb or /EWSIIS log / Test E-mail AutoConfigurationOutlook keeps prompting for a password with Exchange Server: the usual causes and fixes HTTP 404 Not Found from the Autodiscover URLIIS log / Test E-mail AutoConfigurationAutodiscover failing on Exchange Server: fixing SCP, DNS, 401 and certificate errors HTTP 500 Internal Server Error from Autodiscover or MAPI/HTTPIIS log / Test E-mail AutoConfigurationOWA and ECP HTTP 500 errors on Exchange Server: usual causes and how to tell them apart HTTP 503 Service Unavailable from Autodiscover or MAPI/HTTPIIS log / Test E-mail AutoConfigurationExchange components stuck Inactive after an update: ServerWideOffline and requesters Microsoft Exchange is not available. Either there are network problems or the Exchange server is down for maintenance.Outlook"The connection to Microsoft Exchange is unavailable": fixing Outlook on Exchange Server The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.Outlook"The connection to Microsoft Exchange is unavailable": fixing Outlook on Exchange Server The name on the security certificate is invalid or does not match the name of the siteOutlook Security AlertOutlook “The name on the security certificate is invalid”: Exchange URLs vs SAN names The security certificate has expired or is not yet valid.Outlook Security AlertExchange Server certificates: renewing the SAN certificate and the Auth certificate The security certificate was issued by a company you have not chosen to trust.Outlook Security AlertOutlook, Autodiscover and OAB error codes with Exchange Server: a quick reference

Exchange event IDs

Every code in the quick reference “Exchange Server event IDs by source: a quick reference for Transport, ESE, DAG and AD”: what it means, the usual cause and the first check. Open the quick reference

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Event ID 4 (Security-Kerberos): KRB_AP_ERR_MODIFIED error from the serverSystem log (client)Outlook keeps prompting for a password with Exchange Server: the usual causes and fixes Event ID 106 (MSExchange Common): Performance counter updating errorApplication logExchange Server event IDs by source: a quick reference for Transport, ESE, DAG and AD Event ID 129 (ExchangeStoreDB): Page patching was initiated to restore the pageApplication logJET error -1018 and ESE event 474: page checksum corruption in an Exchange database Event ID 258 (MSExchange RBAC): CmdletAccessDeniedException, no management rolesApplication logExchange Server RBAC: roles, scopes and "access denied" in the EAC and shell Event ID 413 (ESE): Unable to create a new logfile, the database cannot write to the log driveApplication logExchange transaction logs filling the disk: backups, circular logging and safe recovery Event ID 474 (ESE): page checksum mismatch, the read fails with -1018Application logJET error -1018 and ESE event 474: page checksum corruption in an Exchange database Event ID 476 (ESE): page contains no page data (-1019)Application logJET error -1018 and ESE event 474: page checksum corruption in an Exchange database Event ID 623 (ESE): the version store has reached its maximum sizeApplication logExchange Server event IDs by source: a quick reference for Transport, ESE, DAG and AD Event ID 1000 (Application Error): Faulting application name: EdgeTransport.exeApplication logPoison message queue and a stuck Submission queue in Exchange: causes and safe fixes Event ID 1003 (MSExchange Front End HTTPS Proxy): unhandled exception, OWA/EAC sign-in loopApplication logExpired Exchange Auth certificate: OWA/EAC redirect loops, Event ID 1003 and hybrid errors Event ID 1005 / 1006 (MSExchange Mitigation Service): action completed, e.g. mitigation appliedApplication logExchange Emergency Mitigation service and AMSI: how they protect on-premises servers Event ID 1008 (MSExchange Mitigation Service): error, for example OCS unreachableApplication logExchange Emergency Mitigation service and AMSI: how they protect on-premises servers Event ID 1026 (.NET Runtime): The process was terminated due to an unhandled exceptionApplication logEvent ID 4999 on Exchange Server: reading MSExchange Common Watson crash reports Event ID 1035 (MSExchangeFrontEndTransport): Inbound authentication failed with error LogonDenied for Receive connectorApplication logExchange Server event IDs by source: a quick reference for Transport, ESE, DAG and AD Event ID 1053 (MSExchange ActiveSync): insufficient permissions to create the device containerApplication logActiveSync not syncing on Exchange Server: quarantine, Event ID 1053 and HTTP errors Event ID 1069 (FailoverClustering): a cluster resource failedSystem logDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 Event ID 1135 (FailoverClustering): cluster node removed from the active failover cluster membershipSystem logDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 Event ID 1177 (FailoverClustering): the Cluster service is shutting down because quorum was lostSystem logDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 Event ID 1309 (ASP.NET): An unhandled exception has occurred (/owa or /ecp)Application logOWA and ECP HTTP 500 errors on Exchange Server: usual causes and how to tell them apart Event ID 1325 (ASP.NET): An unhandled exception occurred and the process was terminatedApplication logEvent ID 4999 on Exchange Server: reading MSExchange Common Watson crash reports Event ID 2004 (Resource-Exhaustion-Detector): low virtual memory conditionSystem logHigh CPU or memory on Exchange Server: what's normal and how to find the real cause Event ID 2014 (MSExchange AuthAdmin): current signing certificate updated (informational)Application logExchange Server certificates: renewing the SAN certificate and the Auth certificate Event ID 2080 (MSExchange ADAccess): topology discovery results (informational)Application logTopology discovery failed (event 2142): reading event 2080 and fixing Exchange DC access Event ID 2112 (MSExchange ADAccess): no Audit Security Privilege on a domain controllerApplication logTopology discovery failed (event 2142): reading event 2080 and fixing Exchange DC access Event ID 2142 (MSExchangeADTopology): Topology discovery failedApplication logTopology discovery failed (event 2142): reading event 2080 and fixing Exchange DC access Event ID 2937 (MSExchange ADAccess): a property points to the Deleted Objects containerApplication logEvent ID 2937 MSExchange ADAccess: fixing HomeMTA and other links to deleted objects Event ID 4113 (MSExchangeRepl): database redundancy check failed, fewer healthy copies than expectedApplication logDatabase copy FailedAndSuspended in an Exchange DAG: find the cause and reseed safely Event ID 4374 (MSExchangeRepl): database availability check failed, fewer copies availableApplication logExchange Server event IDs by source: a quick reference for Transport, ESE, DAG and AD Event ID 4740 (Security): a user account was locked outSecurity log (domain controller)Outlook keeps prompting for a password with Exchange Server: the usual causes and fixes Event ID 4999 (MSExchange Common): Watson report about to be sent (unhandled exception)Application logEvent ID 4999 on Exchange Server: reading MSExchange Common Watson crash reports Event ID 7000 (Service Control Manager): a service failed to startSystem logExchange services disabled or not starting after a CU or security update (error 1058) Event ID 7001 (Service Control Manager): depends on a service which failed to startSystem logExchange services disabled or not starting after a CU or security update (error 1058) Event ID 7040 (Service Control Manager): service start type changed (auto start to disabled)System logExchange services disabled or not starting after a CU or security update (error 1058) Event ID 10047 (MSExchangeIS Mailbox Store): mailbox-level repair request startedApplication logNew-MailboxRepairRequest: fixing logical corruption in Exchange mailboxes Event ID 10048 (MSExchangeIS Mailbox Store): repair request completed successfullyApplication logNew-MailboxRepairRequest: fixing logical corruption in Exchange mailboxes Event ID 10059 (MSExchangeIS Mailbox Store): database-level repair request startedApplication logNew-MailboxRepairRequest: fixing logical corruption in Exchange mailboxes Event ID 10062 (MSExchangeIS Mailbox Store): corruption detected by a repair requestApplication logNew-MailboxRepairRequest: fixing logical corruption in Exchange mailboxes Event ID 12014 (MSExchangeFrontEndTransport / MSExchangeTransport): no certificate for the connector FQDN, no STARTTLSApplication logEvent ID 12014: Exchange can't find a TLS certificate for a connector FQDN Event ID 15004 (MSExchangeTransport): Resource pressure increased (back pressure)Application log452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed Event ID 15005 (MSExchangeTransport): Resource pressure decreasedApplication log452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed Event ID 15006 (MSExchangeTransport): rejecting messages, available disk space below the thresholdApplication log452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed Event ID 15007 (MSExchangeTransport): rejecting message submissions, memory use above the thresholdApplication log452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed Event ID 15021 (HttpEvent): An error occurred while using SSL configuration for endpoint 0.0.0.0:444System logOWA and ECP broken after certificate changes: fixing the Exchange Back End 444 binding

Shell & Active Directory errors

Every code in the quick reference “Exchange Management Shell and Active Directory errors: a quick reference with fixes”: what it means, the usual cause and the first check. Open the quick reference

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A parameter cannot be found that matches parameter name '<name>'.Exchange Management ShellExchange Server RBAC: roles, scopes and "access denied" in the EAC and shell A special Rpc error occurs on server <server>: The certificate with thumbprint <thumbprint> was not found.Exchange Management ShellExpired Exchange Auth certificate: OWA/EAC redirect loops, Event ID 1003 and hybrid errors couldn't create or update the Edge Subscription account on the Edge Transport serverNew-EdgeSubscription (Edge server)EdgeSync failing with "The LDAP server is unavailable": re-creating the Edge Subscription Database is mandatory on UserMailbox.Get-Mailbox -Arbitration / Exchange setupMissing Exchange arbitration mailboxes: the errors they cause and how to recreate them EdgeSync service cannot connect to this subscription because of error "The LDAP server is unavailable."Test-EdgeSynchronizationEdgeSync failing with "The LDAP server is unavailable": re-creating the Edge Subscription Failed to connect to an Exchange server in the current site.Exchange Management Shell (startup)Exchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors SeedInProgressException error FE1C6491Update-MailboxDatabaseCopyDatabase copy FailedAndSuspended in an Exchange DAG: find the cause and reseed safely setup can't create them because the local computer isn't in the same domain and site as the schema masterExchangeSetup.logExchange PrepareSchema and PrepareAD errors: permissions, schema master and AD versions Setup encountered a problem while validating the state of Active DirectoryExchangeSetup.logExchange PrepareSchema and PrepareAD errors: permissions, schema master and AD versions The Active Directory schema isn't up-to-date, and this user account isn't a member of the 'Schema Admins' and/or 'Enterprise Admins' groups.Exchange setup readiness checksExchange PrepareSchema and PrepareAD errors: permissions, schema master and AD versions The Exchange Trusted Subsystem is not a member of the local Administrators group on specified witness server <server>.New/Set-DatabaseAvailabilityGroupDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 The object <identity> has been corrupted or isn't compatible with Microsoft support requirements, and it's in an inconsistent state.Exchange Management Shell (WARNING)Exchange Management Shell and Active Directory errors: a quick reference with fixes The operation couldn't be performed because '<identity>' matches multiple entries.Exchange Management ShellExchange Management Shell and Active Directory errors: a quick reference with fixes The operation couldn't be performed because object '<identity>' couldn't be found on '<DC>'.Exchange Management ShellExchange Management Shell and Active Directory errors: a quick reference with fixes The operation couldn't be performed because object 'Migration.8f3e7716-2011-43e4-96b1-aba62d229136' couldn't be foundExchange Management ShellMissing Exchange arbitration mailboxes: the errors they cause and how to recreate them The proxy address "SMTP:<address>" is already being used by the proxy addresses or LegacyExchangeDN of "<object>".Exchange Management Shell / EACExchange Management Shell and Active Directory errors: a quick reference with fixes The task was unable to create the default witness directory on server <server>. Please manually specify a witness directory.New-DatabaseAvailabilityGroupDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 The term 'New-Mailbox' is not recognized as the name of a cmdlet, function, script file, or operable program.Exchange Management ShellExchange Server RBAC: roles, scopes and "access denied" in the EAC and shell The term 'New-MailboxExportRequest' is not recognized as the name of a cmdlet, function, script file, or operable program.Exchange Management ShellExchange Server RBAC: roles, scopes and "access denied" in the EAC and shell The user "<user>" isn't assigned to any management roles.Exchange Management ShellExchange Server RBAC: roles, scopes and "access denied" in the EAC and shell The well-known object entry ... on the otherWellKnownObjects attribute ... points to an invalid DN or a deleted object.Exchange setup / PrepareADExchange PrepareSchema and PrepareAD errors: permissions, schema master and AD versions The WinRM client cannot process the request. It cannot determine the content type of the HTTP response from the destination computer.Exchange Management ShellExchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors The WinRM client received an HTTP server error status (500)Exchange Management ShellExchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors The WinRM client received an HTTP status code of 403 from the remote WS-Management service.Exchange Management ShellExchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors The WinRM client sent a request to an HTTP server and got a response saying the requested HTTP URL was not available.Exchange Management ShellExchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors The WinRM Shell client cannot process the request. The shell handle passed to the WSMan Shell function is not valid.Exchange Management ShellOWA and ECP broken after certificate changes: fixing the Exchange Back End 444 binding This error is not retriable. Additional information: Access is denied.Exchange Management Shell (Add-ADPermission)Exchange Management Shell and Active Directory errors: a quick reference with fixes This error is not retriable. Additional information: Insufficient access rights to perform the operation.Exchange Management Shell / EACExchange Server RBAC: roles, scopes and "access denied" in the EAC and shell This mailbox database contains one or more mailboxes, mailbox plans, archive mailboxes, public folder mailboxes or arbitration mailboxesRemove-MailboxDatabase / uninstallUninstalling an old Exchange server: mailboxes, connectors and errors that block removal This task does not support recipients of this type. The specified recipient <identity> is of type <type>.Exchange Management ShellRemote mailboxes in Exchange hybrid: Enable-RemoteMailbox, attributes and common mistakes Unable to access file shares on witness server <server>.New/Set-DatabaseAvailabilityGroupDAG cluster problems: lost quorum, file share witness errors and Event ID 1135 Unable to load the type "Microsoft.Exchange.Configuration.Authorization.ExchangeAuthorizationPlugin"Exchange Management ShellExchange Management Shell: fixing WinRM 'Connecting to remote server failed' errors WARNING: Seeding of content index catalog for database '<DB>' failed.Update-MailboxDatabaseCopy (Exchange 2016)Exchange content index Failed or Unknown: fixing search on Exchange 2016, 2019 and SE You don't have sufficient permissions. This operation can only be performed by a manager of the group.Exchange Management Shell / EACExchange Management Shell and Active Directory errors: a quick reference with fixes

Move & migration errors

Every code in the quick reference “Mailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid”: what it means, the usual cause and the first check. Open the quick reference

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550 5.1.1 RESOLVER.ADR.ExRecipNotFound (IMCEAEX) after a mailbox moveNDR550 5.1.1 RESOLVER.ADR.ExRecipNotFound and IMCEAEX NDRs: fixing them with X500 addresses AutoSuspended: initial copy done, request paused before completionGet-MoveRequest StatusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid Cannot find a recipient that has mailbox GUID (public folder migration batch)New-MigrationBatch (Exchange Online)Migrating public folders to Exchange Online: the batch steps and the errors that stop them Completed: move finished; remove the request before moving the mailbox againGet-MoveRequest StatusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid CompletedWithSkippedItems: move finished with items left behind (Exchange Online)Get-MoveRequest StatusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid CompletedWithWarning: move finished but something was skipped or not cleaned upGet-MoveRequest StatusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid Completing: migration batch stuck before it finishesMigration batch statusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid CompletionInProgress: final sync and switch-over runningGet-MoveRequest StatusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid CopyingMessages: MRS is copying mailbox contentGet-MoveRequestStatistics StatusDetailMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid DataConsistencyScore Investigate: skipped items need approval before completionGet-MigrationUser / EACHybrid mailbox migration batches: reading statuses, fixing common errors and completing the move DataConsistencyScore Poor: completion blocked until Microsoft Support reviews itGet-MigrationUser / EACHybrid mailbox migration batches: reading statuses, fixing common errors and completing the move Failed: the move request stopped with a permanent errorGet-MoveRequest StatusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid InProgress: MRS is processing the move requestGet-MoveRequest StatusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid MigrationPermanentException: target mailbox doesn't have an SMTP proxy matching tenant.mail.onmicrosoft.comMigration batch user (Exchange Online)Hybrid mailbox migration batches: reading statuses, fixing common errors and completing the move MigrationPermanentException: Target user already has a primary mailboxMigration batch user / New-MoveRequestMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid MigrationPermanentException: The onboarding move could not be created because user is already being movedMigration batch user (Exchange Online)Mailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid Object 'Migration.8f3e7716-2011-43e4-96b1-aba62d229136' couldn't be found: Migration arbitration mailbox missingExchange Management ShellMissing Exchange arbitration mailboxes: the errors they cause and how to recreate them Queued (migration user): waiting for a free migration slot on the endpointGet-MigrationUser StatusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid Queued: the move request is waiting for MRS to pick it upGet-MoveRequest StatusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid Relinquishing job because of large delays due to unfavorable server health or budget limitationsMove request report (-IncludeReport)StalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves Request was quarantined: The given key was not present in the dictionary (public folder migration)Public folder migration requestMigrating public folders to Exchange Online: the batch steps and the errors that stop them SourceMailboxAlreadyBeingMovedPermanentException: Couldn't switch the mailbox into Sync Source modeMove request / migration user errorMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid StalledDueToTarget_DiskLatency: paused because target disk latency is too highGet-MoveRequestStatistics StatusDetailStalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves StalledDueToTarget_MdbAvailability: paused by the target database availability checkGet-MoveRequestStatistics StatusDetailStalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves StalledDueToTarget_MdbReplication: paused until the target DAG copies catch upGet-MoveRequestStatistics StatusDetailStalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves Suspended: move request paused by an administratorGet-MoveRequest StatusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid Synced with errors / Completed with errors: some users in the batch failedMigration batch statusHybrid mailbox migration batches: reading statuses, fixing common errors and completing the move Synced: initial copy done, waiting for completion (Exchange Online)Get-MoveRequest StatusMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid The call to 'https://<host>/EWS/mrsproxy.svc' timed outHCW log / migration endpointHybrid migration endpoint "could not be completed": fixing MRSProxy and 401 errors The connection to the server could not be completed (migration endpoint)Test-MigrationServerAvailability / HCWHybrid migration endpoint "could not be completed": fixing MRSProxy and 401 errors The HTTP request is unauthorized with client authentication scheme 'Negotiate'Migration endpoint / batch errorHybrid migration endpoint "could not be completed": fixing MRSProxy and 401 errors The Mailbox Replication Service was unable to connect to the remote server using the credentials providedMigration endpoint / batch errorHybrid migration endpoint "could not be completed": fixing MRSProxy and 401 errors The remote server returned an error: (401) Unauthorized (mrsproxy.svc)Test-MigrationServerAvailabilityHybrid migration endpoint "could not be completed": fixing MRSProxy and 401 errors TooManyBadItemsPermanentException: more corrupted items than BadItemLimit allowsGet-MoveRequestStatistics FailureTypeStalledDueToTarget_MdbReplication and failed moves: fixing stuck Exchange mailbox moves TooManyLargeItemsPermanentException: items over the size limit (MapiExceptionMaxSubmissionExceeded)Get-MoveRequestStatistics FailureTypeMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid UserAlreadyBeingMigratedException: The user already has a pending requestMigration batch user (Exchange Online)Mailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid You can't use the domain because it's not an accepted domain for your organization (NotAcceptedDomainException)New-MoveRequest / migration user ErrorSummaryMailbox move and migration errors (MRS): a quick reference for Exchange Server and hybrid

Email gateway rejection codes

Every code in the quick reference “Email gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange”: what it means, the usual cause and the first check. Open the quick reference

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4.3.2 Service not available / Service not active (Exchange transport not accepting mail)Gateway queue / message logExchange components stuck Inactive after an update: ServerWideOffline and requesters 5.3.4 Message size exceeds fixed maximum message size (Exchange size limit)Gateway queue / message log550 5.3.4 ROUTING.SizeLimit and 5.2.3: every Exchange message size limit in one place 421 Sender address blocked (Mimecast Blocked Senders policy matched the IP)Sender's NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 441 4.4.1 Error encountered while communicating with primary target IP address (gateway smart host)Exchange queue LastError441 4.4.1 connection timed out and 421 4.4.2 connection dropped: stuck outbound queues 451 5.7.3 Must issue a STARTTLS command first (Exchange connector requires TLS)Gateway log / Exchange protocol logEmail gateway in front of Exchange Server: connectors, InternalSMTPServers and loops 451 Account outbounds disabled / Account inbounds disabled (Mimecast account setting)Queue LastError / NDREmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 451 Account service is temporarily unavailable (Mimecast: too many concurrent connections)Exchange queue LastErrorEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 451 An open relay is not allowed (Mimecast: connecting IP not authorized)Exchange queue LastError / NDREmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 451 Internal resources are temporarily unavailable (Mimecast greylisting or IP reputation)Sending server queue / Mimecast logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 451 IP Temporarily Blacklisted (Mimecast: sending server over a limit)Sending server queueEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 451 Message ended early (Mimecast: message incorrectly terminated)Sending server queue / NDREmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 451 Recipient Temporarily Unavailable (Mimecast recipient validation not responding)Sending server queue / Mimecast logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 451 The incorrect hostname used for inbounds (Mimecast: MX points to outbound hosts)Sending server queue / NDREmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 451 Try again later (FortiMail greylisting, or recipient verification server unreachable)Sending server queue / FortiMail logFortiMail with Exchange Server: 550 5.7.1 Relay access denied, 451 and recipient checks 451 Unable to process connection at this time (Mimecast at maximum load)Sending server queueEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 452 4.3.1 Insufficient system resources (Exchange back pressure)Gateway queue / message log452 4.3.1 Insufficient system resources: Exchange back pressure explained and fixed 452 Too many recipients (Mimecast: more than 100 RCPT TO per message)SMTP session / queue LastErrorEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 454 4.7.5 The certificate specified in TlsCertificateName of the SendConnector could not be foundExchange queue LastErrorEvent ID 12014: Exchange can't find a TLS certificate for a connector FQDN 454 TLS not available due to temporary reason (Mimecast TLS policy or certificate)Queue LastError / NDREmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 530 5.7.1 Client was not authenticated (Exchange receive connector refusing the gateway)Gateway queue / message log530 5.7.1 Client was not authenticated: fixing anonymous SMTP submission to Exchange 535 Incorrect authentication data / 550 Submitter failed to authenticate (Mimecast SMTP AUTH)Exchange queue LastError / NDREmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 5.7.1 Relay access denied (FortiMail: relay not allowed for the sending server)Exchange queue LastError / NDRFortiMail with Exchange Server: 550 5.7.1 Relay access denied, 451 and recipient checks 550 5.7.54 SMTP; Unable to relay recipient in non-accepted domain (Exchange refusing the gateway)Gateway queue / message log550 5.7.54 Unable to relay: configuring anonymous relay on Exchange Server safely 550 <details of RBL> (Mimecast: sending IP listed on an RBL)Sender's NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 Administrative prohibition envelope blocked (Mimecast Blocked Senders or SPF hard fail)Sender's NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 Anti-Spoofing policy - Inbound not allowed / Rejected by header-based Anti-Spoofing policy (Mimecast)Sender's NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 DKIM Sender Invalid - envelope rejected (Mimecast DKIM check)NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 DMARC Sender Invalid - envelope rejected (Mimecast DMARC check)Sender's NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 Envelope blocked - User Entry / User Domain Entry / Rejected by header-based manually Blocked Senders (Mimecast)Sender's NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 Exceeding outbound thread limit (Mimecast: too many outbound connections)Exchange queue LastError / NDREmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 Invalid Recipient (Mimecast recipient validation found no internal user)Sender's NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 Journal messages past the expiration (Mimecast journaling)Exchange queue LastErrorEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 Local CT IP Reputation - (reject) (Mimecast IP reputation)Sender's NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 Message bounced due to Content Examination Policy (Mimecast)NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 Rejected by header-based Blocked Senders - Block policy for Header From / Envelope Rejected (Mimecast)Sender's NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 550 Rejecting for Sender Policy Framework (SPF) (Barracuda SPF check)Sender's NDR / Barracuda Message LogBarracuda Email Protection with Exchange Server: connectors, smart host and 550 rejections 550 SPF Sender Invalid - envelope rejected (Mimecast SPF check)Sender's NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 552 #5.3.4 message header size exceeds limit (Cisco Secure Email Gateway)NDR / Cisco mail_logsEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 553 This route requires encryption (TLS) (Mimecast TLS policy)Queue LastError / NDREmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 553 This route requires TLS version 1.2 or greater / requires high-strength ciphers (Mimecast)Queue LastError / NDREmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 554 5.4.6 Hop count exceeded - possible mail loop (between gateway and Exchange)NDR / gateway message log554 5.4.6 and 5.4.14 Hop count exceeded: finding and fixing Exchange mail loops 554 Email rejected due to security policies (Mimecast virus, spam or QR code check)NDR / Mimecast rejection logEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 554 IP name lookup failed. No PTR record found for the given IP address. (Barracuda reverse DNS check)Sender's NDR / Barracuda Message LogBarracuda Email Protection with Exchange Server: connectors, smart host and 550 rejections 554 Mail loop detected (Mimecast: 25 hops reached)NDREmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 554 Maximum email size exceeded (Mimecast size limit)NDREmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange 554 Rejected due to spam content / 554 Rejected due to virus (Barracuda content verdict)Sender's NDR / Barracuda Message LogBarracuda Email Protection with Exchange Server: connectors, smart host and 550 rejections 554 Service unavailable; client host [IP or hostname] blocked using Barracuda Reputation (sending IP on the BRBL)Sender's NDR / Barracuda Message LogBarracuda Email Protection with Exchange Server: connectors, smart host and 550 rejections 554 Your access to this mail system has been rejected due to the sending MTA's poor reputation (Cisco)Sender's NDR / Cisco mail_logsEmail gateway rejection codes (Mimecast, Cisco IronPort): a quick reference for Exchange

VSS & backup error codes

Every code in the quick reference “Exchange Server VSS backup error codes: writer states, VSS_E codes and first fixes”: what it means, the usual cause and the first check. Open the quick reference

30
0x800423F1 VSS_E_WRITERERROR_OUTOFRESOURCES: the writer ran out of memory or other system resourcesvssadmin / backup job logExchange Server VSS backup error codes: writer states, VSS_E codes and first fixes 0x800423F2 VSS_E_WRITERERROR_TIMEOUT: the writer timed out between the Freeze and Thaw eventsvssadmin / backup job logMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups 0x800423F3 VSS_E_WRITERERROR_RETRYABLE: the writer hit a transient error; a retry may succeedvssadmin / BETEST / backup job logMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups 0x800423F4 VSS_E_WRITERERROR_NONRETRYABLE: the writer hit an error that will probably recur on retryvssadmin / backup job logMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups 0x8004230E VSS_E_VOLUME_NOT_SUPPORTED_BY_PROVIDER: the chosen provider doesn't support this volumeBackup job logExchange Server VSS backup error codes: writer states, VSS_E codes and first fixes 0x8004230F VSS_E_UNEXPECTED_PROVIDER_ERROR: the provider returned an error code VSS didn't expectBackup job log / Application log (VSS)Microsoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups 0x80042301 VSS_E_BAD_STATE: calls made out of order: the requester skipped initialization or prerequisite stepsBackup job logExchange Server VSS backup error codes: writer states, VSS_E codes and first fixes 0x80042306 VSS_E_PROVIDER_VETO: expected provider error; the provider logged the reason in the event logBackup job log / Application logMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups 0x80042312 VSS_E_MAXIMUM_NUMBER_OF_VOLUMES_REACHED: too many volumes in one shadow copy set (64 maximum)Backup job logExchange Server VSS backup error codes: writer states, VSS_E codes and first fixes 0x80042316 VSS_E_SNAPSHOT_SET_IN_PROGRESS: another shadow copy creation is already in progressBackup job logExchange Server VSS backup error codes: writer states, VSS_E codes and first fixes 0x80042317 VSS_E_MAXIMUM_NUMBER_OF_SNAPSHOTS_REACHED: the volume is already in the maximum number of shadow copy setsBackup job logExchange Server VSS backup error codes: writer states, VSS_E codes and first fixes 0x80042318 VSS_E_WRITER_INFRASTRUCTURE: VSS couldn't contact the writersBackup job log / Application log (VSS)Exchange Server VSS backup error codes: writer states, VSS_E codes and first fixes 0x80042319 VSS_E_WRITER_NOT_RESPONDING: a writer didn't answer the status request: it ended or is stuckBackup job log / vssadminMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups 0x80070005 E_ACCESSDENIED: the caller lacks backup privileges or isn't an administratorBackup job logExchange Server VSS backup error codes: writer states, VSS_E codes and first fixes Event 521 Microsoft-Windows-Backup: Volume Shadow copy operation failed for backup volumesApplication log (Windows Server Backup)Exchange Server VSS backup error codes: writer states, VSS_E codes and first fixes Event 2153 MSExchangeRepl: The log copier was unable to communicate with serverApplication log (MSExchangeRepl)Exchange Server VSS backup error codes: writer states, VSS_E codes and first fixes Last error: Non-retryable error (0x800423F4)vssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups Last error: Retryable error (0x800423F3)vssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups Last error: Timed out (0x800423F2)vssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups State: [1] Stable (with a Last error other than No error)vssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups State: [5] Waiting for completion (VSS_WS_WAITING_FOR_BACKUP_COMPLETE)vssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups State: [7] Failed (VSS_WS_FAILED_AT_PREPARE_BACKUP)vssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups State: [8] Failed (VSS_WS_FAILED_AT_PREPARE_SNAPSHOT)vssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups State: [9] Failed (VSS_WS_FAILED_AT_FREEZE)vssadmin list writersMicrosoft Exchange Writer failed or Retryable error: fixing Exchange Server VSS backups State: [12] Failed (VSS_WS_FAILED_AT_BACKUP_COMPLETE)vssadmin list writersExchange transaction logs filling the disk: backups, circular logging and safe recovery VSS_E_FLUSH_WRITES_TIMEOUT / VSS_E_HOLD_WRITES_TIMEOUT: the system couldn't flush or hold I/O writes for the snapshotBackup job logExchange Server VSS backup error codes: writer states, VSS_E codes and first fixes VSS_E_INSUFFICIENT_STORAGE: not enough storage space for the shadow copyBackup job logExchange Server VSS backup error codes: writer states, VSS_E codes and first fixes VSS_E_REBOOT_REQUIRED: the provider hit an error that needs a restartBackup job logExchange Server VSS backup error codes: writer states, VSS_E codes and first fixes VSS_E_TRANSACTION_FREEZE_TIMEOUT / VSS_E_TRANSACTION_THAW_TIMEOUT: VSS couldn't freeze or thaw the DTC or the Kernel Transaction ManagerBackup job logExchange Server VSS backup error codes: writer states, VSS_E codes and first fixes VSS_E_UNEXPECTED: unexpected VSS error; the code is written to the error logBackup job log / Application log (VSS)Exchange Server VSS backup error codes: writer states, VSS_E codes and first fixes
All 127 guides

Every Exchange Server guide, by area

Troubleshooting guides, how-tos, deep dives and code references for on-premises Exchange Server, Exchange hybrid and the products integrated with it.

All Exchange Server guides

Mail flow 17

Databases & DAG 16

Setup & updates 13

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Client access 14

Management & monitoring 15

Hybrid & migration 14

Lifecycle 5

Third-party integrations 22

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