postscreen is supported on Postfix stable releases 2.9 and 2.8.
Earlier postscreen versions are not part of a stable release, and
are therefore not supported.
There are plenty resources that provide RPMs for Postfix 2.9,
or how to build your own. These are discussed frequently on
this mailing lis
I'm quite locked to running the distributions version of postfix
(currently 2.6.6), but also would very much to take advantage of
postscreen for turning away zombies. I saw in the postfix-2.7.0
announcement that it would be possible to use postscreen from v2.8
with postfix v2.7, and also the POSTSC
