Hello Rocco,
> I've started writing a patch for CVS head that ports the header caching
> used in Maildir and IMAP also to POP. In addition, via $imap_cachedir,
> mutt can cache whole messages and not just headers. I've also started
> porting this feature to POP.
while you're at it you could also support mh style mailboxes. I got once
a feature request for this, but never took the time to do it. But it is
trivial.
Thomas