I have recently migrated from Exchange 2003 to Exchange 2007 and I am trying to remove my legacy 2003 machine. I am getting the error that there are still mailboxes on this store. During the migration I moved some mailboxes and exported others to .pst files and deleted the mailboxes. I have used the ADSIEdit.msc tool to look at the homeMDBBL value and the only thing listed there are Microsoft System Attendant, SMTP, and SystemMailbox entries. I have also removed all of the legacy connectors and routing groups to try and clean things up. I'm at a loss of what to look at next.
Any help or direction would be great.