[MlMt] Best way to auto-archive trash in gmail?

[Michael Hucka]

I recently had to switch to Gmail as my imap server [1].  It seems that 
Gmail auto-deletes mail from the trash after 30 days.  I'm looking for a 
way to preserve all my mail.  Does anyone have a scheme to preserve mail 
permanently rather than let it be deleted?  For example, is there a way 
to have MailMate (or another piece of software) periodically and 
automatically move mail out of the Trash into a folder (or even another 
imap server) for archiving?

I'm a long-time unix & mac user and a software developer too, so I'm not 
afraid of command lines or daemons or writing some software myself.  If 
someone has already done this or can advise about dead-ends to avoid, 
I'd appreciate the tips.

Best regards,
MH

[1] To avoid the inevitable snarky "don't use gmail" comments, let me 
just say I don't have a choice in the matter for the time being.