The Exchange Mailbox Replication Service does not have full permissions to handle the mailbox.Another Exchange Administrator may be migrating the same mailbox to another database due to which the mailbox is locked.There may be some other causes which can lead to the error mentioned above – It also shows some possible causes like the mailbox is locked, Microsoft Exchange Mailbox Replication service lacks necessary permission for syncing the mailbox. The error mentions that it cannot sync the source mailbox with the destination. The mailbox is locked, or the Microsoft Exchange Mailbox Replication service doesn't have the correct permissions.įailureType: SourceMailboxAlreadyBeingMovedTransientException.

This could be because another administrator is currently moving the mailbox into the destination database,

One such error is following –Ĭouldn't switch the mailbox into Sync Source mode. But occasionally you may have to face some error related to the syncing of a mailbox. While migrating Exchange mailbox from one database to another, the Exchange Administrator does not need to sync the data to each folder, but Exchange Server does it automatically.

Office 365 sync files