exim & procmail & mutt & MMDF

[Edmund GRIMLEY EVANS]

In my .muttrc I have set mbox_type="MMDF", so most of my mailboxes are
in MMDF format. Therefore, if I add a procmail rule that appends onto
an existing mailbox, the result is unusable, because neither exim nor
procmail knows about MMDF, as far as I can tell. This is inconvenient.
But what's the best solution? Is it at all possible to make procmail
deliver to MMDF mailboxes?

Edmund