[Dovecot] Online backup with dovecot

Hi!

Do you guys/girls (whichever you prefer) know if it's possible (i.e. in some semitransparent/easy way) to incorporate an online backup system? If the mail is older than a set amount of days it gets compressed.

I want my mail storage size to shrink but on the other hand I want to keep the mails I get and have them easily readable :)

I'm thinking of symlinks and some kind of gzip fuse filesystem... Please save me ,)

/yosh