On Thu, Jun 16, 2022 at 07:35:20PM -0400, Wietse Venema wrote:
> Bob Proulx:
> > Is there a transport mapping equivalent to match against the MX host
> > instead of against the the recipient address? That's really what is
> > desired here. I didn't think such a feature existed yet.
>
> it would require a Postfix lookup table that returns MX hosts for
> a domain,
>
> pipemap:{domain-to-mx, inline:{ {.google.com = slow:} }
>
> plus some safeguard to avoid doing this for local deliveries.
Transport resolutiont that does remote DNS lookups will be a prohibitive
performance bottleneck on systems delivering a steady non-trivial stream
of mail. The queue manager is not multi-threaded, and each recipient
domain can/will incur some delay.
I would not recommend doing this until (some nebulous day) the queue
manager can perform asynchronous transport resolution for multiple
recipients in parallel.
--
Viktor.
