QPSMTPD is a flexible smtpd daemon written in Perl.
Apart from the core SMTP features, all functionality is implemented in small “extension plugins” using the easy to use object oriented plugin API.
Anti-Spam
- Innovative spam fighting ideas can easily be implemented and tested with qpsmtpd plugins. One successful examples is the check_earlytalker plugin (disconnects most viruses and many spam engines before we even say hello!).
- Support for DNS Black Lists like the Spamhaus lists.
- Support for Domain-Based Blacklist Zones lists.
- Support for Milter filters (yes, those written for sendmail) with the milter plugin
- Greylisting with Gavin Carr’s denysoft_greylist plugin
- DomainKeys support with the domainkeys plugin
- Integrated support for SpamAssassin
- Virus scanning with ClamAV
- Many others …