[Dovecot] what best for anti-spam filter?

[Markus Schönhaber]

24.07.2012 10:49, Morten Stevens:

> No, greylisting is really a bad solution. It is not RFC compliant and 
> delays the mail traffic.

No. Rejecting mail with an temporary error is perfectly RFC compliant.
It happens all the time without greylisting. Because the authors of the
SMTP RFC knew that there are many different possible reasons why a mail
server might temporarily be unable to receive mail, they added the 4yz
responses to it.

With greylisting done right, only a very small part of (wanted) incoming
mail is delayed. And for the rest: e-mail isn't guaranteed to be a
real-time communication channel.

-- 
Regards
  mks