> On Nov 28, 2018, at 11:43 PM, Stefan Bauer <cubew...@googlemail.com> wrote:
>
> The use case is only for mx service so there will be only incoming mail for
> same domain in same smtp session.
>
> I assume that remote mail servers will not combine mail delivery in same smtp
> session when destination domains differ (even though they have same mx)
The assumption is invalid. Exim IIRC can deliver multiple recipients
in a single envelope, if there's a shared MX host. So can Postfix,
if the destination MX is a statically configured nexthop.
You might also get more recipients in one envelope than will
be accepted downstream.
In any case, Postfix does not support routing without queueing.
If this is a hard requirement, you'll need a different MTA.
--
Viktor.
