On Mon, Aug 24, 2015 at 10:01:27PM +0200, Andrzej A. Filip wrote:
> Claus Assmann <ca+postfix-us...@esmtp.org> wrote:
> >> With SMTP there is no per-recipiet end-of-data reply, and a
> >> reject reply will block mail for all recipients.
> >
> > AFAICT PRDR can do that -- it's implemented in exim and some other MTA.
> > However, it's barely used...
>
> One way to "encourage" its implementation would be to reject connections from
> "dubious" reputation hosts unless PRDR (Per-Recipient Data Responses) is
> negotiated/requested.
That's not going to happen. Non-support for PRDR is an extremely
poor indicator of client reputation. If PRDR is used to impute
reputation, the early adopters will be primarily spammers.
--
Viktor.
