junkfilter

a junk e-mail filter system for procmail

Copyright 1997-2001 Gregory Sutter <gsutter@zer0.org>

$Id: README,v 2.22 2001/05/28 08:08:35 gsutter Exp $

Contents:
	0.  What is junkfilter?
	1.  Use of junkfilter
	2.  How to get junkfilter
	3.  Mailing lists
	4.  Installation instructions
	5.  Sample .procmailrc file
	6.  Helping improve junkfilter
	7.  Contributors

0.  What is junkfilter?

	junkfilter is a spam filtering program built on top of the
	procmail email delivery system.  the goal is to create filter
	sets that will block as much spam as possible.  junkfilter
	functions equally well at the individual-user level or at the
	system level; however, since procmail can be slow and mail
	volumes high, its general use at the system level is discouraged.
	junkfilter makes an an excellent second stage spam filter, coupled
	with a first-stage MTA-based ruleset.

	As junkfilter requires the procmail system, it can only be
	used on a Unix-like system.  Procmail does not work on 
	Windows; this is a FAQ:
	http://www.zer0.org/procmail/mini-faq.html#nt
	
1.  Use of junkfilter
	junkfilter is copyright 1997-2001 Gregory Sutter.
	All rights reserved.

	junkfilter is licensed under a BSD-style license.  See the 
	LICENSE file for the full text.

2.  How to get junkfilter
	The junkfilter web page is http://junkfilter.zer0.org/
	junkfilter and this documentation are available at the web site.

	junkfilter has also been instantiated at SourceForge.  The
	project is http://sourceforge.net/projects/junkfilter/

	junkfilter's CVS tree is available from
	http://sourceforge.net/cvs/?group_id=13498

3.  Mailing lists
	junkfilter has two mailing lists, an announce list and a
	general-purpose list.  If you wish to receive announcements
	of new releases, subscribe by sending a message to
	junkfilter-announce-subscribe@groups.yahoo.com.  If you wish
	to also receive general mail from a two-way mailing list, 
	subscribe by sending a message to
	junkfilter-users-subscribe@groups.yahoo.com.  Thanks to
	egroups.com, now part of Yahoo!, for hosting these lists.

4.  Installation of junkfilter
	We assume you've already got procmail installed and running
	properly, as this is explicitly a "junk email filter system for
	procmail".  Consult the procmail documentation or the FAQ,
	http://www.zer0.org/procmail/
	if you need help installing procmail.

	Set the $PMDIR variable.  It is recommended that you make a
	directory ".procmail" in your home directory and a symlink from 
	$HOME/.procmailrc to $HOME/.procmail/procmailrc:
		mkdir -m 755 $HOME/.procmail
		mv -i $HOME/.procmailrc $HOME/.procmail/procmailrc
		ln -s $HOME/.procmail/procmailrc $HOME/.procmailrc
	If you do this, you can set PMDIR=$HOME/.procmail

	Place the junkfilter files wherever you want them.
	$PMDIR/junkfilter or $PMDIR are likely choices.  Set $JFDIR in
	your procmailrc (for junkfilter to run) and in your shell
	configuration files (for the "jf" utility) to the directory in
	which you placed junkfilter.  Be sure that $JFDIR is set in your
	current session, and use the "jf" utility to parse the data
	files and build expressions from them:
		./jf build all
	You will find your $JFDIR populated with the regexp data files.

	To call junkfilter, place a line in your procmailrc file that
	reads:  INCLUDERC=$JFDIR/junkfilter
	This will call junkfilter.  All other junkfilter files are called
	from within this first file.

	You now have a basic junkfilter setup.  You now need to configure
	junkfilter to fit your every desire.  Edit junkfilter.config and
	change the various options from 0 to 1 and vice-versa.  0 means
	"false"; 1 means "true".  A given piece of code will only
	execute if it is set true.  Please read the comments at the
	beginning of each one before changing anything.

	If you are installing junkfilter as a systemwide solution, and
	want each user to have customizable defaults, you can copy the
	junkfilter.config file to their home directories, calling it
	".junkfilterrc".  junkfilter will check $HOME/.junkfilterrc for
	local configuration overrides each time it is called.
	
	The file junkfilter.user is provided as a convenient place for
	you to store your own personal junk filtration recipes.  If you
	follow the recommended format (given at the beginning of that
	file), junkfilter will treat your recipes the same as the rest
	of the files.  The "user" section is the first section checked
	when junkfilter is called.  In the distribution, the stock
	junkfilter.user is called junkfilter.user-default so that your
	personalized copy is not overwritten when you upgrade later.
	If you enable any of the user- rules or options in junkfilter,
	you MUST be sure that the files referenced by them in 
	junkfilter.config exist!  This means that you must rename the
	files distributed as *-default, removing the dash and the word
	"default".  If you don't do this, all of your mail will end
	up in the slag heap. 

	You can change the default action of jf to whatever you prefer.
	The only action command in junkfilter is to set the variable
	JFEXP to a relevant piece of text.  It is up to you to then
	take some action.  Since you've called junkfilter from your
	.procmailrc file, you can easily take action depending on the
	output (in the JFEXP variable) of junkfilter.

	The whitelist feature is a way of making sure that certain
	people/mails are not blocked, even if junkfilter would block
	them ordinarily.  The implementation of the whitelist does not
	break compatibility with older releases of junkfilter, but
	does require that a more complex set of recipes be used to
	decide whether or not to take action on the message.

	I use this action in my .procmailrc directly after the
	INCLUDERC=$JFDIR/junkfilter statement:

	:0
	* JFEXP ?? .
	{
		:0 f
		* JFSTATUS ?? 1
		| formail -i "X-junkfilter: $JFVERSION" \
			-i "X-Spammer: $JFEXP"

		:0 E :
		| formail -i "X-junkfilter: $JFVERSION" \
			-i "X-Spammer: $JFEXP" >> junkmail
	}

	Instead of this, you can change it to whatever you prefer.  The
	most common change will be the name of the mailbox in which the
	junk mail is stored.  You can change it to /dev/null if you wish,
	but remember that no matter how good the filter, mistakes will
	be made.  The author does NOT recommend immediately discarding
	any mail filtered by junkfilter. 

5. Sample .procmailrc file that calls junkfilter
	Please see the file procmailrc.sample for a working example
	of how to call junkfilter from your procmailrc.  If you have
	no other procmail recipes, you can simply install this in 
	$PMDIR and make a symbolic link to it from your $HOME.

6.  Helping improve junkfilter
	If you know procmail, or would like an example of a working
	procmail-based tool of medium complexity to play with or 
	hack around on, take a look at the junkfilter code.  There 
	are lots of ways to improve the system.  Please submit 
	bugs (and preferably patches) to the management systems at
	SourceForge:
		bugs:  
	http://sourceforge.net/tracker/?atid=113498&group_id=13498&func=browse
		patches:
	http://sourceforge.net/tracker/?atid=313498&group_id=13498&func=browse

	Bugs, patches, questions, and comments may also be posted
	to the junkfilter-users mailing list or to the author.  Note
	that emailing the author directly has the lowest probability
	of receiving a timely response. 

	junkfilter users who wish to see more of their spam caught by
	the filter in the future may wish to forward their spam which
	was _not_ caught by junkfilter to an email address set up for
	this purpose.  To do this, you should enable JF_OPT_SENDBACK in
	your junkfilter.config file.  It's near the end.  This will
	enable some settings that will mark each email that passes
	through junkfilter.  If a spam has the headers added by this
	setting, it will be accepted at the email address
	<junkfilter-misses@lists.sourceforge.net>.  Spam sent here may
	be analyzed and used to improve junkfilter. 

	Only spam that has been processed by junkfilter, yet not
	caught, will be of use.  junkfilter must have JF_OPT_SENDBACK
	enabled to be of use.

7.  Contributors to junkfilter
	Many people have contributed to junkfilter in various ways; the
	author would like to thank the following people in particular:

	Matthew Hunt <mph@pobox.com>, who co-developed junkfilter for the
			 	      first few months.  Thanks, Matt!
	Jeff A. Earickson <jaearick@colby.edu>
	Era Eriksson <era@iki.fi>
	Brian Goetz <brian@quiotix.com>
	Philip Guenther <guenther@gac.edu>
	Brad Knowles <brad@his.com>
	Bryan D. McMeen <bryan.mcmeen@symtecinc.com>
	John Perry <perry@jpunix.com>
	Edward Sabol <sabol@alderaan.gsfc.nasa.gov>
	David Tamkin <dattier@wwa.com>
	John Wilkes <john@wilkes.com>
	and
	the procmail mailing list <procmail@Informatik.RWTH-Aachen.DE>

