Version 4 (modified by Kim Minh Kaplan, 12 years ago)


Copyright 2007 by Kim Minh Kaplan

Greyfix is the greylisting policy daemon for Postfix written by Kim Minh Kaplan. Greylisting is an anti spam technique described by Evan Harris. Postfix is a popular mail transport agent developped by Wietse Zweitze Venema. Greyfix uses Postfix policy mechanism to enable greylisting with Postfix.


Latest version

greyfix-0.3.3.tar.gz (PGP signature)

  • BUGFIX expire correctly triplets
  • Add option =--dump-triplets=, =--reject-action= and =--greylisted-action=.
  • Really delete expired triplets from the DB.
  • Note that =451= reject code is probably better than =DEFER_IF_PERMIT=.


  • Low and tunable resource usage and high efficiency. The program is written in C and uses Berkeley DB to track mailers. By itself it allocates memory only for a single request and the Berkeley DB library can be configured to use very few RAM.
  • Integrates with Postfix's master daemon. Postfix will shutdown greyfix when it is not used completely freeing its runtime resources.
  • No administrative burden. Everything happens "automagically".
  • No need for a database server. Uses Berkeley DB.