How to: Move Arbitration Mailboxes in Exchange 2010

Error: This mailbox database contains one or more mailboxes, mailbox plans, archive mailboxes, or arbitration mailboxes. To get a list of all mailboxes in this database, run the command Get-Mailbox -Database . To get a list of all mailbox plans in this database, run the command Get-MailboxPlan. To get a list of archive mailboxes in this database, run the command Get-Mailbox -Database -Archive. To get a list of all arbitration mailboxes in this database, run the command Get-Mailbox -Database -Arbitration. To disable a non-arbitration mailbox so that you can delete the mailbox database, run the command Disable-Mailbox . To disable an archive mailbox so you can delete the mailbox database, run the command Disable-Mailbox -Archive. Arbitration mailboxes should be moved to another server; to do this, run the command New-MoveRequest . If this is the last server in the organization, run the command Disable-Mailbox -Arbitration -DisableLastArbitrationMailboxAllowed to disable the arbitration mailbox. Mailbox plans should be moved to another server; to do this, run the command Set-MailboxPlan -Database .

If you are like me you already moved all your user mailboxes out of the database but you probably forgot about arbitration mailboxes. If you are curious about them you can read more about them here: Exchange 2010: What is an arbitration mailbox?. Anyway, the issue here is that the arbitration mailboxes get placed in the first mailbox database you create, hence your SBS Exchange machine. All you have to do is run the following command to move those mailboxes to your new database on a different server:

Using the Exchange Management Shell execute the following

“Get-Mailbox –Arbitration | New-MoveRequest –TargetDatabase DatabaseName”

That should work fine most of the time, but if you want to be more specific you can run the following command:

Get-Mailbox -Arbitration -Database “Mailbox Database SOURCE” | New-MoveRequest -TargetDatabase “Mailbox Database DESTINATION”

The first command will get all the arbitration mailboxes across the enterprise while the second one will just pick from the database you specify (your SBS computer in my case). For most users it won’t matter which one you use but for a large enterprise it does make a world of a difference. Hope this helps!