[Dovecot] support for UW-style mbox

[Rich West]

Yes, you are correct.  I'm not sure what I was thinking when I phrased
it that way. :)  Linux derivatives use procmail as the default MDA,
while other platforms use different MDA's to do the final delivery. 
Sendmail acts as an MTA (Mail Transport Agent) and does not directly
touch the end user's mailboxes.

To clarify the answer to the original question, the MDA and MTA are
*very* closely related as they work hand-in-hand.  The MDA, not dovecot,
is the one that does the final delivery of email to the user's mailbox.

-Rich

> I believe sendmail does no file delivery. It uses the configured local
> mailer to deliver to local users, and it's up to the local mailer's
> configuration to decide where to send the message. (On Red Hat derived
> systems, such as Fedora, procmail is configured as the default local
> mailer. See sendmail.mc.)