Mark Alan:
> On Wed, 9 Feb 2011 15:18:39 -0500 (EST), Wietse Venema
> <wie...@porcupine.org> wrote:
>
> > postscreen currently does not implement greylisting - smtpd(8)
> > currently can do that with policy daemons.
>
> Yes but they do it very late in the process
> smtpd_recipient_restrictions =
> ...
> reject_unauth_destination,
> check_policy_service inet:127.0.0.1:11111
> ...
>
> If possible, expensive tests like check_policy_service should be in
> postscreen, i.e., outside any real smtpd and processed even before
> postscreen's first 451.
postscreen can implement built-in greylisting at very low run-time
cost, but this is a low priority (i.e. perhaps by the end of 2009)
because greylisting is already available via Postfix SMTP server
policy delegation.
Expensive tests should be used only for things that cheap tests
can't stop. Expensive tests have no place in postscreen, because
that would make a single program a performance bottleneck.
Wietse
