Viktor Dukhovni:
> > On 11 Aug 2021, at 11:00 am, Matt Corallo <ps...@mattcorallo.com> wrote:
> >
> > Hmm, well I suppose consider this a feature request for
> > sender_dependent_relay_transport_maps or sender_dependent_transport_maps :)
>
> No such feature fits into a single-key lookup design.
>
> You're looking to exempt specific sender (domains) from the recipient-based
> nexthop of specific recipient domains. This is a multi-key transport
> decision, and supporting this requires a radically different design.
>
> So the feature request is extremely unlikely to be actionable.
We solved a multi-criteria decision problem with check_policy_service
in Postfix access maps, where a policy server can make a ruling
based on multiple attributes. Whet helped here was that many smtpd
processes make policy requests in parallel, so that individual
response latencies do not add up.
Routing decisions are different - they are requested by a single
queue manager process, so that individual response latencies will
add up unless that part of the scheduler is also parallized (just
the handling of delivery requests is parallelized). But then who
would implement the server that makes routing decisions?
Maybe time to revive the vintage-1997 ideas for a configurable
trivial-rewrite service. I abandoned that because it started
to look like sendmail.cf.
Wietse
