Using DCC To Filter Message Bodies

Most Linux uses procmail as the local deliver agent. Junkfilter
(http://sourceforge.net/projects/junkfilter/) is an excellent procmail
heuristics junk detector. Problem is that it does do false positives.

You can do something like this in /etc/procmailrc:

JFDIR=/usr/local/etc/junkfilter
INCLUDERC=$JFDIR/junkfilter

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

:0 E
{
:0 f
| formail -i "X-junkfilter: $JFVERSION" \
-i "X-Spammer: $JFEXP"

:0 f
|/usr/local/bin/dccproc -w whiteclnt -t many

}
}



What this does is do a junkfilter check, puts a X-Spammer in if it matches 
and does a dccproc. 


The current procmail call uses both the junkfilter whiteclient and the 
dcc whiteclient.

If the junkfilter whitelist is hit, only the header in inserted, no 
dccproc. If dcc whitelist is hit, it does not get sent to the dccd.

The only addition that may be considered is a extra rule to put the mail 
to /dev/null. The ruleset above will protect only future e-mails.