A local mailbox move in Exchange 2013 fails with the error that the System Attendant Mailbox cannot be opened. I thought System Attendant was a thing of the past!
Exchange 2013 doesn’t have system attendant mailbox or even the System Attendant service (mad.exe).
But, the error clearly mentions about the failure to open the attendant mailbox. Though System Attendant mailbox & service have been removed from Exchange 2013, the object is still present in the configuration partition.
But, that was not the cause of the error. Exchange 2013 has a new arbitration mailbox “Migration.8f3e7716-2011-43e4-96b1-aba62d229136” with a display name “Microsoft Exchange Migration”.
In my case, the database hosting this arbitration mailbox was dismounted for some reason. I mounted the database back and the move was successful. In short, this arbitration mailbox is required for successful mailbox moves.
If you have deleted it by mistake or it doesn’t exist in your Exchange (for whatever reason), you can always re-create the AD account by running Setup.exe/PrepareAD. Once the account is created, configure a mailbox for the account by running the command below.
Enable-Mailbox –Arbitration –identity “Migration.8f3e7716-2011-43e4-96b1-aba62d229136”