Forum Discussion
Random Exchange Server to 365 migration batch fails with the error "SourceMailboxAlreadyBeingMoved"
I'm running a migration for a small customer (about 400 mailboxes). half of the mailboxes are migrated just a couple of random mailboxes failed with this error. Has anyone faced/worked around this issue?
I've tried following with no success:
-Tried after a server restart
-Tried creating a new batch
---- Error ----------------------------------------------------------------
Data migrated: 46.29 MB (48,542,751 bytes)
Migration rate:
Error: SourceMailboxAlreadyBeingMovedPermanentException: Couldn't switch the mailbox into Sync Source mode. This could be because of one of the following reasons: Another administrator is currently moving the mailbox. The mailbox is locked. The Microsoft Exchange Mailbox Replication service (MRS) doesn't have the correct permissions. Network errors are preventing MRS from cleanly closing its session with the Mailbox server. If this is the case, MRS may continue to encounter this error for up to 2 hours - this duration is controlled by the TCP KeepAlive settings on the Mailbox server. Wait for the mailbox to be released before attempting to move this mailbox again. --> -->
We've had this error a lot lately. Seems to be a backend problem with Microsoft. Try resuming the move request a few times. It may help to delete and re-create it as well. Sometimes we see this error for a few days when resuming the move request...then it will come good. Other times we have to delete it and recreate and we will get a failure straight away, but a few days later it will be fine 🤷
Hello VidRocksKay,
I have the same problem.
First synchronized successfully. From one day to the next this error...I will write a solution if I find one...
Have you already found a solution?
Best regards
Daniel
