Patrick Ben Koetter:
> * Claus Assmann <postfix-users@postfix.org>:
> > Per RCPT filtering is a feature that is often asked by ISPs who
> > offer anti-spam/virus for their customers: some pay for additional
> > filtering.
>
> In Germany you either reject globally in session, and stick with
> the law, or you reject post-queue per recipient.
>
> Adding functionality to reject pre-queue per recipient would be
> very welcome.
To make per-recipient end-of-data replies useful with Postfix, PRDR
would need to be supported by at least one third-party content
inspection mechanism (such as Amavisd-new or Milter), because I see
no obvious user interface for PRDR with Postfix header/body_checks.
- SMTP-based filters such as Amavisd-new would use the PRDR protocol
to send per-recipient end-of-data replies.
- Milter-based filters would use an extended Milter protocol and
libmilter API to send per-recipient end-of-data replies.
The Milter protocol extension would involve new elements something
like SMFIF_PRDR (a feature flag to announce the capability) and
SMFIR_PRDR (one reply per recipient, each formatted as with
SMFIR_REPLYCODE). If we can freeze the details, then it could be
in Postfix 2.9, which is due early 2012.
Wietse
