With Exchange 2003, if you wanted to create Active Directory accounts based on the list of disconnected mailboxes in the mailbox database, you could use the Mailbox Export Wizard which was a part of the Mailbox Recovery Center. Before that, you could have used MBCONN, a tool we had for that purpose. That functionality would let you create a LDF file for AD import, based on the list of disconnected mailboxes in the mailbox database, in case you needed to bulk create