Exchange Server
On-premises Exchange: transport errors, NDRs, TLS, hybrid configuration and cumulative updates.
60 articles
TooManyBadItemsPermanentException
TooManyBadItemsPermanentException: the move stops on corrupt mailbox items
TooManyBadItemsPermanentException halts a move once bad items pass the limit. Learn how to size BadItemLimit safely and audit what you…
StorageTransientException
StorageTransientException: the mailbox is busy or over quota during a move
StorageTransientException means the store was locked, moving or full when MRS tried. Learn which transient faults clear alone and which…
TargetUserAlreadyHasPrimaryMailboxException
TargetUserAlreadyHasPrimaryMailboxException and other stuck move requests
TargetUserAlreadyHasPrimaryMailboxException means the target object already holds a mailbox. Learn how to clear stale move state and restart.
MapiExceptionNoReplicaAvailable
MapiExceptionNoReplicaAvailable: the public folder hierarchy will not open
MapiExceptionNoReplicaAvailable means clients cannot reach a public folder mailbox. Learn how hierarchy routing breaks and how to restore it.
MapiExceptionPartialCompletion
MapiExceptionPartialCompletion: public folder migration stalls part way through
MapiExceptionPartialCompletion leaves a public folder batch half finished. Learn how to find the failing folder and finish the migration cleanly.
Event ID 12014
Event ID 12014: Exchange cannot find a transport certificate for this domain
Event ID 12014 means no certificate matches the FQDN on a send or receive connector. Learn how to bind the…
0x80090327
0x80090327 and 0x800B0109: Exchange TLS fails on certificate validation
0x80090327 and 0x800B0109 mean the certificate chain failed validation during TLS. Learn how to fix trust, expiry and private key…
0x80090331
0x80090331 algorithm mismatch: legacy TLS blocks Exchange from Microsoft 365
0x80090331 means no shared cipher or protocol is left between the two servers. Learn why old builds fail TLS 1.2…
MapiExceptionTooManyMountedDatabases
MapiExceptionTooManyMountedDatabases: Standard Edition hits its database cap
MapiExceptionTooManyMountedDatabases means the edition limit of five databases is reached. Learn how to confirm the edition and lift the cap.
0xC004F074
0xC004F074: the Windows Server hosting Exchange cannot reach a KMS host
0xC004F074 leaves the Windows Server hosting Exchange unactivated and nagging. Learn the KMS and DNS checks and the licence that…
Event ID 9646
Event ID 9646: a client blew past the Exchange session or object limit
Event ID 9646 fires when one client opens more sessions or folders than allowed. Learn how to find the offender…
Event ID 226
Event ID 226 and Event ID 9519: an Exchange database will not start
Event ID 226 with Event ID 9519 means the store could not start a database. The hexadecimal code inside the…