#	File: 		spewhosts.rc
#	Description:	procmail script for ISP not relayed through their
#			own mailservers.
#	Author:		Sean B. Straw
#	Source:		<http://www.professional.org/procmail/spewhosts.html>
#	Copyright:	Portions copyright (c) 2000-2003, Sean B. Straw
#	Disclaimer:	<http://www.professional.org/procmail/disclaimer.html>
#	Licensing:	Free for use by the procmail community.
#	Support:	Visit the official procmail discussion list to ask
#			procmail questions.  If you need custom procmail
#			work performed (including modifications to this
#			rcfile), the author is available for paid consulting.
#	Limitations:	There is no included support for reducing a 
#			host.domain to the base domain.
#	Requires:	egrep (external program)
#
#
# This is a procmail filter intended to identify (using an external datafile)
# messages where certain hosts used in the From: address should be paired
# with a specific sending host in the Received: headers.
#
# DO NOT AUTO-SUBMIT MESSAGES TO SPAM DATABASES BASED SOLELY UPON THE
# RESULTS OF THIS SCRIPT.
#
# This file is dependant upon some externally defined variables, and also
# utilizes a "SPAMMISHNESS" system described elsewhere in the authors
# writings.

# ==========================================================================

# First, skip this entire process if we're processing a recognized mailing
# list.  Some strip the received lines, and that renders these checks
# invalid.
:0
* LISTNAME ?? ^^^^
{
	# unset SPAMVAL (just in case)
	SPAMVAL

	# set a default spamlevel (overridden in the spewhosts.list file)
	SPAMLEVEL=+100

	# Check the envelope first (we need to extract the domain part).
	:0
	* ENVFROM ?? @\/.*
	{
		CL_MATCH=$\MATCH
		:0h
		WATCHEDMAIL=|egrep -i ^$CL_MATCH[[:space:]] $SPAMDIR/spewhosts.list
	}

	# Now, only if WATCHEDMAIL is non-empty
	:0A
	* WATCHEDMAIL ?? ^[-_\.a-z0-9]+[ 	]+[-+=0-9]+[ 	]+\/[^ 	].*
	* 1^0
	* $ -1^1 ^Received:.*\>by\>+[-_\.a-z0-9]*${MATCH}
	{
		# extract spammishness from the WATCHEDMAIL string
		:0
		* WATCHEDMAIL ?? ^[-_\.a-z0-9]+[ 	]+\/[-+=0-9]+
		* 9876543210^0 MATCH ?? ^\/[-+0-9]+
		* 9876543210^0 MATCH ?? ^\/
		{
			SPAMVAL="${MATCH:-$SPAMLEVEL}"
		}

		SPAMMISHNESS="${SPAMMISHNESS}${SPAMVAL}"
		SPAMNOTES="${SPAMNOTES}SPAM: ${SPAMVAL} From service doesn't appear in Received lines${NL}"
	}

	# then, From: - ONLY IF DIFFERENT from the envelope
	# (no need to double-penalize a sender for ACTUALLY sending mail
	# from the same address as their From:)
	:0
	* $ ! ENVFROM ?? ^^$\CLEANFROM^^
	* ! FROM_DOMAIN ?? ^^^^
	{
		CL_MATCH=$\FROM_DOMAIN
		:0h
		WATCHEDMAIL=|egrep -i ^$CL_MATCH[[:space:]] $SPAMDIR/spewhosts.list
	}

	# Now, only if WATCHEDMAIL is non-empty
	:0A
	* WATCHEDMAIL ?? ^[-_\.a-z0-9]+[ 	]+[-+=0-9]+[ 	]+\/[^ 	].*
	* 1^0
	* $ -1^1 ^Received:.*\>by\>+[-_\.a-z0-9]*${MATCH}
	{
		# extract spammishness from the WATCHEDMAIL string
		:0
		* WATCHEDMAIL ?? ^[-_\.a-z0-9]+[ 	]+\/[-+=0-9]+
		* 9876543210^0 MATCH ?? ^\/[-+0-9]+
		* 9876543210^0 MATCH ?? ^\/
		{
			SPAMVAL="${MATCH:-$SPAMLEVEL}"
		}

		SPAMMISHNESS="${SPAMMISHNESS}${SPAMVAL}"
		SPAMNOTES="${SPAMNOTES}SPAM: ${SPAMVAL} From service doesn't appear in Received lines${NL}"
	}
}

# ==========================================================================

# The module which includes this one should take action based on variables
# which are set in the recipes above.