Wietse Venema has released postfix 2.1-RC5 yesterday, and this is expected to be the final Release Candidate of postfix 2.1-RELEASE.

The key features of postfix 2.1 is drastically improved anti-spam mechanisms. A sample greylist perl script has been added and is usable.

Greylisting is essential for Phantasm Mail System 3.0. It will slightly delay if a mail server is not contacted with you in a certain period, however, it is quite effecient on blocking spammers and with OpenBSD’s pf mechanism, it will waste the time and disk space and resources of the spammer.