Retrieving Email from a Deleted Mailbox

EmailXtender 4.5 - I have a Exchange 2003 server on top of a Windows 2003 server using EmailXtender.  I have been asked to retrieve the email from a user who's mailbox has since been deleted.  Normally I would use their SMTP address in the mailbox field and this definitely finds data but it does not seem to find everything.  Much of this mail was originally on a Exchange 5.5 server and the email was exported to PST and reimported when we upgraded to Exchange 2003 (not sure if that matters or not).

Is this how you do this or is there another (better) way of doing it?

TIA!

Martin