Hello - I am moving my mailboxes to new DB's in order to recover space (defrag). What is interesting is that some of the mailbox's that are moved leave a mailbox in the source with just a few items. For instance - I move user1. It moves succesfully. If I look at the properties of the mailbox it shows it is now in the target DB. But if I do a get-mailbox on the source DB, user1 still shows up but with only one or two items in it. If I attempt to move it again, it says its already in the target DB. Any ideas? I have a lot of mailboxes to move yet.... Thanks!!

Hello, Those might be stale entries and when you run Clean-MailboxDatabase it would mark it for the deletion. No need to worry about it since user object is associated with correct mailbox on new server. I think this might happen if mailbox is opened in outlook or by some other process when you moved mailbox.

I think this is related to Article ID: 940757 . My ultimate goal is to remove the default mailbox database. I only have to move about 30 more users. My hope is that removing the DB will take care of the 'stale' mailboxes. Is there a way to manually move the system mailboxes from that default DB to the other db I created?

Yes correct stale entries will be taken care while removing DB. You don't have to really worry about system mailboxes (basically systemattendant mailbox only) because system attendant service will take care automatically (internally it changes HomeMDB attribute of SA mailbox) and requires SA service. I wouldn't do manually since it will be taken care automatically. Exchange Special Mailboxes Part 2 - System Attendant mailbox http://blogs.technet.com/evand/archive/2004/12/21/329172.aspx