Mailbox migration to or from Office 365 dedicated/ITAR (vNext) results in mailboxes in the cloud and on premises


After you migrate a mailbox to or from Office 365 dedicated/ITAR (vNext), the mailbox exists both in the cloud and on premises. In the migration statistics report, a transient error is reported.


A transient error caused the Exchange Mailbox Replication Service (MRS) to consider the move complete. Therefore, the MRS didn't convert the original mailbox object to a mail user.

You should export the mailbox move statistics for review. To do this, run the following commands, depending on whether the mailbox move was done in a batch or individually.

Batch move
  1. Get-MigrationBatch | fl Identity
  2. Get-MigrationBatch -IncludeReport -Identity <> | fl
Single move
  1. Get-MoveRequest | fl Identity
  2. Get-MoveRequestStatistics -IncludeReport -Identity <> | fl
In the migration statistics report, Status and StatusDetail will be listed as Completed instead of indicating that a mailbox move failed:
Status: Completed
StatusDetail: Completed
Additionally, the following error will be listed:
Transient error TimeoutErrorTransientException has occurred. The system will retry (1/60).
Relinquishing job because the mailbox is locked.
Then, the following text will appear. It indicates that MRS considers the move complete.
Mailbox move is already finished. The HomeMdb value matches the destination database for the primary mailbox move.


To fix this issue, manually remove the original mailbox. If the original mailbox is in the cloud, you can submit a support incident online  to Microsoft Online Services Support. Or you can contact Microsoft Online Services Support by telephone .

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Article ID: 3116331 - Last Review: Nov 16, 2015 - Revision: 1