One of this week’s students brought up a good question in relation to Mailbox management and removal. If you don’t see the mailbox appear in Disconnect Mailboxes view after a removal - “Can i run a “cleanup agent” like i used to do in Exchange 2003?”
There is a new Cmd-let to facilitate this process now in 2010 …
Clean-MailboxDatabase "serverdatabase name"
The process will scan AD service for disconnected mailboxes that are not yet marked as disconnected in exchange store and update it.