If the mailboxes are on the same machine is there any reason why you can't simply concatenate the mailbox files without troubling any network servers.

MTUs go to great lengths to ensure integrity of mail, minimizing the risk mail gets lost, or mailboxes corrupted. You may not want to just "concatenate files". What if a disk or system fails halfway your concatenation? Is it an acceptable risk that you don't know what you copied succesfully, when the system beneath you fails?

Abigail