How Does Procmail Work w/ MTA?

carlosinfl · 01-31-2008, 04:40 PM

I noticed in my Postfix mail server running Debian 4.0 there is an option for procmail and I was wondering what exactly does Procmail do and how does it fit into the mix of Postfix MTA?

Here is the entry specifically:

Code:

swordfish:~# cat /etc/postfix/main.cf | grep "procmail"
#mailbox_command = procmail -a "$EXTENSION"

frndrfoe · 01-31-2008, 05:01 PM

Procmail can redirect mail system wide using /etc/procmailrc or per user using ~/.procmailrc.
It is useful for redirecting mail through virus scanners or spam filters. users can individually decide if they want to use such services and configure server side email redirection, sorting, and whatever you can think of. If your building a multi user system, I highly recommend it.

carlosinfl · 01-31-2008, 05:04 PM

So do you recommend I enable that line I have commented out in my main.cf? I see what you're saying like if I want to re-direct all email labeled SPAM from Spamassassin into a ~/.spam directory. Makes sense, right?

Thanks!

frndrfoe · 01-31-2008, 05:16 PM

I haven't worked with postfix so I am not sure if that is the only step to enabling it. I see a thread like this http://www.irbs.net/internet/postfix/0609/0322.html and wonder if it's more configuration than a one-liner.

It is pretty much a one-liner in sendmail but thats a different animal.

dive · 01-31-2008, 08:28 PM

Quote:

Originally Posted by Carlwill

So do you recommend I enable that line I have commented out in my main.cf? I see what you're saying like if I want to re-direct all email labeled SPAM from Spamassassin into a ~/.spam directory. Makes sense, right?

Thanks!

Yes - in my .procmailrc I send straight to /dev/null:

Code:

:0fw
 | spamassassin

 :0:
 * ^X-Spam-Flag: YES
 /dev/null

You can also make rules to sort out mail into folders by subject etc. Very useful.