auto-expunge feature?

[Mark Felder]

GMail has an IMAP feature for clients that never seem to want to expunge 
called "auto-expunge". I've been using Apple mail clients (Mail.app, iOS 
Mail) a lot lately and I find it annoying that when I delete messages 
they are only marked as deleted and not expunged. When I log into my 
webmail client I see them wasting visual space, greyed out. There is no 
option to immediately expunge with these clients; instead the clients 
handle it based on the amount of time they've been marked deleted which 
each client seems to track. The closest I can get to auto-expunge on 
Mail.app is a setting for expunging immediately when quitting the 
application, but if you leave it running all the time that isn't very 
helpful...

It would be nice if there was a similar feature for archiveopteryx. I 
have no idea if this is bad behavior, but I could certainly find it 
useful. The built-in retention policy is already a nice safety net, so 
I'm not personally concerned about losing messages due to accidental 
deletions.