pilgrim: Sorry i was late with the advice! Remember, if you're in 10.3 and using a Firewire drive, be careful! There are issues with 10.3 and Firewire drives ...

clayperion: What you may be experiencing is mail trying to apply mail rules to what you're dragging into your IN box, and the rule that's flagging one or more of the emails you're moving is possibly attempting to file the email(s) in a mailbox that no longer exists. That's one possibility anyway. Good luck!

Cheers

Robin
http://www.tikouka.net/mailapp/