Thunderbird Problem

[Scott Kitterman]

The key issue here, based on your reporting, is mbox versus maildir.

This brings up another possibility that wasn't in my original list.  To use 
Thunderbird with maildir is via imap, so as you suggest the trick is to run 
a local mail delivery agent (MDA) which could serve the files to 
Thunderbird..  I've not heard of using rsync for this before.  Using 
Fetchmail to bring the mail from the remote mail server to a local MDA is a 
more typical approach.

The configuration of all this is non-trivial.  I'd suggest the OP is still 
better off finding an e-mail program that does maildir natively, but this 
is definitely another way to do it.

Scott K