Getmail / procmail / ???

[Derek Broughton]

Michael Satterwhite wrote:

> I'm wanting to setup getmail / procmail on my system. I'm unsure of
> exactly what each piece is supplying, however, and how the mail eventually
> gets to my email client (in this case, kmail).
> 
> I understand that Getmail is bringing the mail from the Pop3 server. 

I use Fetchmail, rather than Getmail, but if memory serves, the process is
identical (I tried Getmail - not as good as fetchmail :-) ).

(f|ge)tmail retrieves a message from a mail server and then has to put it
somewhere.  This means it needs an MDA (mail delivery agent) or MTA (mail
transport agent).  The usual process for fetchmail is to use local SMTP -
it just opens port 25 and talks SMTP to the server.  Alternately, they
access the mail system by piping the message through sendmail - which is
always an alias of the MTA whether using sendmail, postfix, exim, qmail,
etc.  The mail system knows how to get a message into the right mbox or
maildir file for each user.

The final option is to use an explicit MDA like procmail or maildrop.  They
work like the full MTA but only for the local system.  They also handle
various filtering rules that may not be implemented on the MTA - you might
put procmail between an MTA and your local mail store to sort incoming mail
into different folders (some MTAs can do that, but why reinvent the wheel).

> What 
> exactly is Procmail adding (I'm assuming it's needed)? After it goes
> through these two, how do I get the output to my email client?

Generally, procmail will put the mail into the location specified in your
$MAIL variable, which your mail client will be pointing to.  In my case, it
puts the mail in /var/mail/$USER/ which is a maildir, and dovecot (my IMAP
server) gets the mail from there.  My local mail clients connect to the
IMAP server.
-- 
derek