Giles Coochey:
>
> On 03/04/2019 14:58, Wietse Venema wrote:
> > Giles Coochey:
> >> I notice that some mails that pass the sendmail server get rejected by
> >> postfix, because the sender domain appears to be NXDOMAIN. I assume
> >> these are temporary 400 rejections (to cope with a failed DNS) -?
> >> Sendmail keeps these in the queue for a number of days and eventually my
> >> postmaster receives a NDR - the NDR can't be sent to the originator
> >> because the reply email is not valid anyway.
> > If you don't want Postfix to reject this mail then DO NOT SPECIFY
> > reject_unknown_recipient_domain.
>
> I think I've checked that already:
>
> # grep? reject_unknown_recipient_domain /etc/postfix/main.cf
> #
OK, now try unknown_sender_domain.
> But perhaps one of these settings causes it?
Or you could end this guessing game, if you can give the full Postfix
logfile record. You may obfuscate domains, hosts, IP addresses, and
users, but not the text that describes the nature of the error.
The point is, out-of-the-box Postfix does not give a hoot about the
sender email address. You configured Postfix to reject the sender,
and you will configure Postfix to stop doing that.
Wietse
