Question : Mailbox is missing after moving from Exchange 2003 to Exchange 2007

Hello.  I am migrating from Exchange 2003 to Exchange 2007.  The Exchange 2007 server has been in place for several months now and I have been slowly moving mailboxes from the 2003 server to the 2007 server.  Over the past few months I have moved about a hundred or so mailboxes (we only have about 200 total in our org) and have experienced no problems.  

Last weekend I moved another batch of mailboxes.  No warnings or errors were reported by the mailbox move applet.  Today a user is reporting that he cannot access his email.  I look in EMC under Recipient Configuration -> Mailbox and the user is not there.  When I view the user object in ADUC I see the Exchange Mailbox Store value is correct.

In the event logs I see the event 1006 for the move-mailbox task started.  The Source and Destination databases are both correct.  I then see a few normal informational events regarding named property creations in the database, and then the Event 1007 Move-mailbox finished event.  After that the normal ActiveSync events (upgrade from earlier version of Microsoft Exchange) occur.

From the event logs, everything worked perfectly.  When I do a "get-mailbox -Identity (username)" the response "Get-Mailbox : Username is not a mailbox user."

The mailbox does not appear under 'Disconnected Mailbox' either.

Answer : Mailbox is missing after moving from Exchange 2003 to Exchange 2007

Run the cleanup agent do you see the mailbox in disconnected mailbox now?

Run the following powershell command:

Clean-MailboxDatabase MailboxDatabaseName