On Mon, Aug 28, 2017 at 04:46:19PM +0300, Deniss wrote:
> > You could use:
> >
> >
> > http://www.postfix.org/postconf.5.html#sender_dependent_default_transport_maps
> >
> > but only when the destination domain is not a "relay" domain or
> > similar, that is, only if mail for the destination in questin just
> > goes whereever the MX records point with no transport overrides
> > beyond (sender_dependent_default_transport_maps) which selects a
> > sender dependent *default* transport.
>
> I'm using permit_auth_destination and it does not play without
> relay_domains.
If the destination domain is yours and the senders are remote
untrusted clients, then indeed "default_transport" won't do
unless you're a backup MX host (in that case it is possible
to allow relaying for the domain via "check_recipient_access",
and the default transport will find the right primary MX host).
> well, looks like I found few solutions:
>
> 1. change transport using FILTER via check_sender_access in
> smtpd_sender_restrictions - fine until there is no other filter action
This would be wrong for multi-recipient email when some recipients
are local, or in any case should not be sent to the same destination.
> 2. alter nexthop with sender_dependent_relayhost_maps - require
> additional address on the backend
This has no effect on concurrency limits, but with a different
nexthop you get a new pool of concurrency slots, so if traffic to
that destination is light and the active queue is not full, that
will help avoid queueing behind a other traffic that is sharing a
low-throughput channel.
> As I understand concurrency limits will differ from ones on default
> route in both cases.
Not differ, just be separate.
> IMO it may be useful to allow alter transport in
> sender_dependent_relayhost_maps as well in future releases of postfix
No, that would not be a good idea, since transport selection needs to
be recipient based.
--
Viktor.
