[vps-mail] proctut0: Procmail Basics

[Scott Wiersdorf <scott@xxxxxxxxxxxx>]

An updated version of this document may be found at:

    <http://www.perlcode.org/tutorials/procmail/proctut/>

Scott
-- 
Scott Wiersdorf
scott@xxxxxxxxxxxx

NAME
    Procmail Basics

SYNOPSIS
    This tutorial will discuss what procmail is and why it might be useful
    to you in controlling what comes into your mailbox.

DESCRIPTION
    Procmail, at its heart, is a mail processor; it PROCesses MAIL. Part of
    its process is to scan the mail and look for anything you've told it to
    look for, and then to deliver the mail where you tell it to be
    delivered. Simple.

    Now the trick is to figure out how to tell it what to look for and what
    to do with it once it's found what it's looking for. A little
    terminology is appropriate here.

  Introduction to recipes

    Procmail uses recipes to determine what to look for and what to do once
    it's found what it's looking for. A simple procmail recipe might look
    like this:

        :0:
        * ^From:.*joe@schmoe\.org
        joe

    This recipe looks for email messages from 'joe@xxxxxxxxxx' and delivers
    them to a file called joe. Once an email is delivered (i.e., written to
    a file), procmail stops processing[1] immediately[2] and all subsequent
    recipes are ignored.

    If an email message does not match a recipe (e.g., in this case, if the
    message were not from 'joe@xxxxxxxxxx'), the email moves on to the next
    recipe until a matching recipe is found. If no matching recipes are
    found, the next recipe file is examined.

  Where are the recipes?

    Procmail looks for recipes in the following locations[3] (and in this
    order):

        /usr/local/etc/procmailrc (or /etc/procmailrc)
        $HOME/.procmailrc

    Once procmail finds one of the above files, it reads it for recipes. If
    the file does not exist, or none of the recipes match the email,
    procmail will read the next file until a matching recipe is found. If no
    matching recipes are found, the mail message is said to "drop off the
    end" and is delivered to the default mailbox for the recipient (e.g.,
    /var/mail/scott).

SUMMARY
    Procmail is a powerful tool for scanning and redirecting incoming mail.
    Procmail uses recipes to determine what to look for and what to do with
    mail. Recipes are found in the /usr/local/etc/procmailrc and
    $HOME/.procmailrc files[3]; procmail searches each of these files in
    turn until a matching recipe is found. Once a matching recipe is found,
    procmail delivers the mail and processing immediately ceases[2] and
    subsequent recipes are skipped[1].

NOTES
    [1] Unless you've made a *copy* of your email with the 'c' flag.
    Discussed in subsequent articles.

    [2] We do not discuss *non-delivering* recipes here. We'll talk about
    those in later articles.

    [3] There is another location that is searched after the global
    /usr/local/etc/procmailrc and before the user's $HOME/.procmailrc file.
    This location is a directory and is located at
    /usr/local/etc/procmailrcs. Discussed in subsequent articles and in
    procmail(1).

PREVIOUS
    This is the first procmail tutorial in a series.

NEXT
    *Anatomy of a Procmail Recipe, Part I*

SEE ALSO
    procmail(1), procmailrc(5), procmailex(5)

AUTHOR
    Scott Wiersdorf <scott@xxxxxxxxxxxx>

COPYRIGHT
    Copyright (c) 2003 Scott Wiersdorf. All rights reserved.

REVISION
    $Id: proctut0.pod,v 1.2 2003/08/21 17:04:57 deep Exp $