Jaros?aw Rafa:
> W dniu wto, 12.04.2022 o godzinie 13?52?+0200, u?ytkownik Matus UHLAR -
> fantomas napisa?:
> > On 12.04.22 11:21, Yves-Marie Le Pors Chauvel wrote:
> > > Using Postfix 3.5.6 on debian 11, I would like to know if there is
> > > any
> > > possibility not to use an alternative MX for outbound email
> >
> > MX is for inbound e-mail by definition
>
> I think what the OP meant is that recipient domain has two MX-es and
> the goal is that the Postfix doesn't try the second MX in case the
> first one rejects with 4xx but defers the message immediately (for
> this specific recipient domain).
This could be accomplished with a transport_maps entry that resolves
to an SMTP client with smtp_mx_session_limit=1.
/etc/postfix/transport
example.com one-mx-only:
/etc/postfix/master.cf
one-mx-only .. .. .. .. .. .. smtp
-o smtp_mx_session_limit=1
Do "postmap /etc/postfix/transport" after editing the file.
Wietse
