Qmail
How to Check whether an SMTP client is an open SOCKS proxy before accepting mail from it – Qmail
Here is the checksocks program. #!/bin/sh if tcpclient -T 3 “$TCPREMOTEIP” 1080 true 2>/dev/null >/dev/null then export RBLSMTPD=”Port 1080 open at $TCPREMOTEIP” fi eval “exec $*” To use it, include it somewhere between tcpserver and rblsmtpd in your qmail-smtpdinvocation. For example: tcpserver -x tcp.smtpd.cdb \ -vR -u 82 -g 81 -l `hostname` 10.1.2.3 smtp \ [...]
How to Install qmail-badmailfrom-wildcard patch
Qmail-smtpd will reject every recipient address for a message if  the envelope sender address is listed in badmailfrom. A line in badmailfrom may be of the form @host, meaning every address at host To install: cd /src/qmail-1.03 fetch http://tomclegg.net/software/patch-qmail -badmailfrom-wildcard patch < qmail-badmailfrom-wildcard.patch make qmail-smtpd install -m 755 qmail-smtpd /var/qmail/bin/qmail-smtpd To refuse mail from any sender which ends [...]
How to Install and Configure qmail-qfilter
Qmail-qfilter provides a convenient way to pass each incoming email message through a series of filters, each of which may reject or modify the message. This happens before the message enters the queue, so rejects do not become bounce messages. Instead, the client is told immediately that the message was not accepted. Filters In order [...]
How to Install and Configure qmail on Linux
Qmail is a modern SMTP server which makes sendmail obsolete, written by Dan Bernstein, who also has a web page for qmail. qmail is a secure package. You can download netqmail 1.06 (Redhat RPMs, and Debian .debs, HP-UX, Gentoo, and OpenBSD ports) and redistribute qmail for free. A number of large Internet sites are using [...]