Since the hosting service that we use has a paltry 200 mb, we're using gmail as a repository of our mails. It works spectacularly well, for an ugly hack, but there have been incidents where mail has dissappeared off gmail. We haven't been affected, but i'd like to be as sure as possible.
We DO have a spare linux box that runs odds and ends that we can't use as a mail server proper since its on a dynamic ip address.
I'd like to 1) periodically download via imap or pop, email on a gmail account. Sent mails get forwarded there so its a non issue
2) add them to a mail account which can be accessed over IMAP - this will give us the option of using the same mail clients we use, re-export to gmail or other IMAP capable hosts, or an internal web client.
I'm not sure how to go about doing this, since most mailservers are mailservers, not backup boxes.