What is the supported way to use RBL lists?

If you've never been spammed, consider yourself very lucky. Most e-mail users are all too familiar with Unsolicited Bulk E-mail (UBE), aka "spam". Most of it is advertisements for sex sites, chain letters, and other scams. Back in the days of old, up until around 1998 or so, most MTA's on the Internet wererelays, i.e., they would accept mail from anyone for anyone, even if neither sender nor recipient was local. Spammers userelays, if they can find any, to deliver their spam. It covers their tracks, redirects the backlash toward the "innocent" relay site, and saves them lots of CPU time and network bandwidth.

Suchrelays are considered very bad form these days, and several anti-spam vigilante groups have created a mechanism for identifyingrelays and other common sources of spam so they can avoid accepting SMTP connections from them.

rblsmtpd is an RBL SMTP Daemon. It sits between tcpserver and qmail-smtpd and rejects connections from systems identified on one of these lists.

For example, to run rblsmtpd under tcpserver, try something like:

#!/bin/sh

QMAILDUID=`id -u qmaild`

NOFILESGID=`id -g qmaild`

MAXSMTPD=`cat /var/qmail/control/concurrencyincoming`

exec /usr/local/bin/softlimit -m 2000000 \

/usr/local/bin/tcpserver -v -R -H -l 0 -x /etc/tcp.smtp.cdb -c "$MAXSMTPD" \

-u "$QMAILDUID" -g "$NOFILESGID" 0 smtp /usr/local/bin/rblsmtpd\

-r relays.ordb.org /var/qmail/bin/qmail-smtpd 2>&1

rblsmtpd was previously available as a separate utility, but is now bundled with ucspi-tcp.

rblsmtpd was written by Dan Bernstein, who maintains a web page for it at cr.yp.to/ucspi-tcp/rblsmtpd.html.

This answer was found in Life With Qmail by Dave Sill