Microsoft Exchange Server system mailboxes are also known as “Arbitration” mailbox. Exchange Server use these arbitration mailboxes for various tasks like eDiscovery Search Metadata, Admin audit logs, OAB, Mailbox Migration, UM data like menus, dial plan etc. These mailboxes are automatically created when you setup first exchange server and the process of preparing Active Directory creates these accounts in root domain of your active directory during the process of AD preparation. These mailboxes can be seen via Exchange Management Shell by running the following EMS cmdlet.
Below are the arbitration mailboxes created by Exchange Server during the installation with a disable AD account in root active directory under users OU.
Today I have been working on Exchange Server 2010 to Exchange Server 2016 upgrade and got the following error message with a user mailbox migration batch.
Microsoft has the solution documented in the KB article 2812509. The reason for error is that the migration mailbox is either not enabled or was deleted. When you use the New-MigrationBatch cmdlet, the Migration mailbox must exist and be enabled or else you won’t be able to migrate the mailboxes.
Although the migration arbitration mailbox is created upon initial installation of your Exchange server 2016, this account can be corrupted or being deleted by mistake. You can easily re-create this account by running the following EMS cmdlets.
How to Fix It?
- Firstly step is to ensure that the account Migration.8f3e7716-2011-43e4-96b1-aba62d229136 does not exist
Get-Mailbox -Arbitration | fl name, alias
- Prepare your active directory by running the following cmdlet in Windows PowerShell
.\Setup /PrepareAD /IAcceptExchangeServerLicenseTerms
- Once the AD preparation is completed, Verify that the account exist under default Users OU in root active directory
- Enable the Arbitration mailbox used for migration
Enable-Mailbox -Arbitration -Identity “Migration.8f3e7716-2011-43e4-96b1-aba62d229136”
- Configure the migration arbitration mailbox as below
Set-Mailbox “Migration.8f3e7716-2011-43e4-96b1-aba62d229136” -Arbitration –Management:$true