This is an old revision of the document!

= DNS “greylisting”=

IN MX 5 spamvoid.aufbix.org. IN MX 10 your.real.mx.server IN MX 15 spamvoid.aufbix.org.

Most spam/viruses will hit primary and backup MX server with lower priority. Spamvoid.aufbix.org points to a VALID IP, but connections on port 25/tcp (smtp) will (and must) timeout.

= greylisting =

= sender address verification =
= RFC2820/2821 rules =
= helo checks =
= policyd-weight =