Unable to uninstall Exchange server 2010 while mailbox database has un-moved arbitration mailboxes

Hi

It has been a while since I did a transition for Exchange server 2010, and last days I did one…

Today I was doing the final part of it which is decommissioning the old server, I did it but I had to do some extra work to finish the job…

I had moved all the users mailboxes to the new server, and the database seems empty, but in fact, it was not, because there were some system mailboxes called Arbitration mailboxes

So when trying to uninstall the server, I got the error about existing mailboxes still on the database of the server I want to remove!

All I had to do is move these mailboxes to the new server and I was done (NEVER REMOVE THESE MAILBOXES UNLESS YOU ARE REMOVING THE LAST SERVER IN THE ORGANIZATION)

• The first step is to list all the arbitration mailboxes in the database (databases if you had more than 1 database on the old server):

Get-Mailbox -Database "[YOUR_DATABASE_NAME]" -Arbitration | ft -Auto

• Then, I needed just to move the mailboxes to the new server:

Exchange 2010 RTM cmdlet:

Move-Mailbox "[ARBITRATION_MAILBOX_FULL_NAME]" -Arbitration -TargetDatabase "[NAME_OF_DATABASE_ON_NEW_SERVER]"

Exchange 2010 SP1 cmdlet:

New-MoveRequest "[ARBITRATION_MAILBOX_FULL_NAME]" -TargetDatabase "[NAME_OF_DATABASE_ON_NEW_SERVER]"

(Replace the colored words with the actual values from the output you will see in the PowerShell KEEP THE QUTATION MARKS)

You have to do this move for all mailboxes you will see, the size of each mailbox should be very small, mostly KBs, and sometimes will get to few MBs…

Use Get-MoveRequest if you are on SP1 so you can track the status of the move process…

Well, that’s all for this, I hope this will be useful for you