Matt Corallo:
> I tried variations of this but never could get it to work - as far as I could
> tell the nexthop is fully resolved by the
> time we get to the smtp daemon, so there aren't any relevant settings to
> override or otherwise set the default on the
> nexthop there.
In the FILTER command you specify transport AND nexthop. There is
nothing to be resolved BEFORE the SMTP client.
Wietse
> Thanks,
> Matt
>
> On 8/11/21 17:37, Wietse Venema wrote:
> > Matt Corallo:
> >>
> >>
> >> On 8/11/21 16:52, Wietse Venema wrote:
> >> > If the sender address can override the routing, even if the recipient
> >> > would otherwise be delivered locally, then that would be a recipe
> >> > for mailer loops with the potential for mail explosions. This is
> >> > why we have sender_dependent overrides for default transports and
> >> > relay hosts, and avoid such stability problems.
> >>
> >> Ah! Understood, indeed, the setup I've had to fall back to has some risk
> >> of routing loops, though with some care to
> >> hopefully ensure it can't ever actually be hit. I guess the only solution
> >> is multi-key lookups, which would be nice, but
> >> understood that its likely very nontrivial to add :).
> >
> > Would this do the job:
> >
> > /etc/postfix/main.cf:
> > smtpd_sender_restrictions = hash:/etc/postfix/sender_access
> >
> > /etc/postfix/sender_access
> > example.com filter smtp-example-com:relay-for-example-com
> > ...
> >
> > /etc/postfix/master.cf:
> > smtp-example-com .. .. .. .. .. .. smtp
> > ...
> >
> > It avoids the need for another instance. Postfix should break a
> > mailer loop that delivers to itself.
> >
> > Wietse
> >
>
