[ILUG] Procmail not working on incoming mail?

[Kenn Humborg]

On Thu, Feb 24, 2000 at 12:06:27AM +0000, Dave Neary wrote:
> 
> Sorry...information overload. I was tring to be thorough.
> 
> I only added the .forward after the problem made itself known. The
> procmail stuff in the sendmail.cf file is the default setup (with some
> tweaking from install-sendmail scripts), and on any other box I've used
> the combination, I have had no problems.
> 
> fetchmail -v only gets the mails once, but it gets mails which it has
> previously gotten (doesn't delete mail from the server, and doesn't check
> procmail rules to eliminate duplicates, presumably). The multiple messages
> are in /var/spool/mail/dave, after fetchmail does it's thing.

Well, there's your problem.  All fetchmail does (in this case) is pretend
to be a plain old POP or IMAP mail reader (like Netscape/Eudora/Outlook Express)
and download mail from your ISP.  Once it receives a message, it hands it
to sendmail (your mail _transfer_ agent) to send it to the destination.
Sendmail decides it's for local delivery and invokes procmail to do the
final step of appending to /var/spool/mail/$USER.  (Procmail can do other
funky things when delivering, but that's of no consequence here.)

Read the docs on fetchmail and learn how to tell it to delete the mail
from the ISP after downloading it.

> Possibly I don't understand well enough how mail gets downloaded, or how
> procmail got invoked. I assumed that it would be invoked automatically
> when mail arrives in the local mailbox. I guess it's possible that it's
> only invoked if mail's transfered by sendmail, as opposed to fetched by
> fetchmail. But to be honest, I don't really understand what's happenning
> at all.

sender->sendmail->your ISP->fetchmail->sendmail->procmail

MUA: mail user agent (e.g. mutt, Netscape mail)
MTA: mail transfer agent (e.g. sendmail, postfix, qmail)
MDA: mail delivery agent (e.g. procmail)

fetchmail is an MTA that looks like an MUA to your ISP.

Later,
Kenn