qpsmtpd

Receiving incoming email and making it available to your users via POP3 or IMAP is only the first half of running a Message Transfer Agent (MTA). The other half is to relay outgoing email from your users to the world.

We don't want to run an open relay, of course, so we we need some form of authorization.

[08-11: New installation on 10.3/8.6.0]

The qpsmtpd daemon started as a replacement daemon for the qmail-smtpd SMTP receiver from the qmail mail transport agent (MTA), but it can also be used with other MTAs. qpsmtpd is written in pure Perl and can be customized easily. It consists of a core that implements a complete SMTP server, and a number of plug-ins that enhance the operations of the server. These plug-ins allow for the checking of recipients and senders, as well as virus scanning, spam checking, blocking lists (DNS and RHS), SMTP AUTH and TLS. If you like to tweak, you can adapt qpsmtpd to almost any environment and task.

In this article I collect information that I've gathered from various sources and customized for installing qpsmtpd on Suse and Plesk.