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Friday, March 26, 2010

Clean Removal of the first Exchange 2010 Mailbox server or mailbox database.

When you try to remove the Exchange 2010 mailbox server or will remove the firstly installed mailbox database for what ever reason, you will probably find that the removal finishes unsuccessful showing you following error message:
"Uninstall cannot continue. Database 'Mailbox Database 0186314254': This mailbox database contains one or more 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 arbitration mailboxes in this database, run the command Get-Mailbox -Database -Arbitration. Before you can remove this mailbox database, you must disable, move, or remove user mailboxes and move arbitration mailboxes. "
Some people tend to use ADSIEDIT, but I was wondering if there wasn’t any cleaner way to do it. Do not get me wrong, I often use ADSIEDIT and find it a very helpful tool. But Syntax without the glamor of the GUI has its own edge. Oh and by the way, you will have to use EMS (who uses EMC anyways ;)).
But what are those Arbitration Mailboxes?
Arbitration Mailboxes are used for the Exchange 2010 feature of Moderated Transport:
Using the moderated transport feature in Microsoft Exchange Server 2010, you can require all e-mail messages sent to specific recipients be approved by moderators. You can configure any type of recipient as a moderated recipient, and Exchange 2010 Hub Transport servers will ensure that all messages sent to those recipients go through an approval process.
In any type of organization, you may need to restrict access to specific recipients. The most common scenario is the need to control messages sent to large distribution groups. Depending on your organization's requirements, you may also need to control the messages sent to executive mailboxes or partner contacts. You can use moderated recipients to accomplish these tasks.
These Arbitration Mailboxes are created in the first mailbox database on the first Exchange 2010 mailbox server in the organization. What can we do to remove or move them to another mailbox database?
If you have installed other Exchange 2010 mailbox database in your organization you can move these arbitration mailboxes to another mailbox database.
Move arbitration mailboxes:
Get-mailbox –Arbitration | New-MoveRequest –TargetMailboxDatabase %TargetDatabase%
This will move the 3 Mailboxes to the mailbox database you have specified.
To check the status of the move request:
Get-MoveRequest –Status
This move request takes a very short time you will see that the move request has already finished by the time you checked the status. Once the move request has been completed you can clear the move request.
Get-MoveRequest | Remove-MoveRequest
Now what if you want to reinstall your exchange server, and do not have an Mailbox database to move these Arbitration Mailboxes to?
If you are planning on reinstalling your Exchange Server, you need to keep these accounts to which these mailboxes are linked. These accounts are created when doing the domain prep for Exchange 2010.
Remove the Arbitration Mailboxes
Get-Mailbox -Arbitration | Disable-Mailbox -Arbitration
By using the disable cmdlet, you will only remove the mailboxes and not the accounts which are linked to it.
Now if you are fed up with Exchange 2010 and want to remove the whole Exchange 2010 Environment, you can always remove the Arbitration Mailboxes and accounts:
Get-Mailbox -Arbitration | Remove-Mailbox -Arbitration -RemoveLastArbitrationMailboxAllowed
You can now completely remove the Exchange 2010 from the mailbox server, and remove the remaining Exchange 2010 server.
Now what if you mistakenly have removed these arbitration accounts, and really want them back. Well than again you have several options:
You could always return these accounts from the Active Directory Tombstone using tools as ADRESTORE, QUEST Object Restore for Active Directory..., or off course rerun the PrepareAD switch from the Exchange 2010 Setup:
Setup /prepareAD


  1. Get-mailbox –Arbitration | New-MoveRequest –TargetMailboxDatabase %TargetDatabase% should actually be

    Get-mailbox –Arbitration | New-MoveRequest –TargetDatabase %TargetDatabase%

  2. I'd love to do this... I really would... desperately. But I have no idea what DB I can MOVE these to, on the new server. I've tried the 4 DBs, DB01-04, but I get an error. Here's the situation. We had a physical server, we created a VM for exchange, and now we want to move the arbitration stuff to the new server (other boxes moved fine). It seems like the problem is I don't have a targetdatabase that works to move to. This is a system thing, this arbitrage, so, any ideas what I'm missing?

    Thanks a lot,