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.


  • 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 …