On Tue, Jan 31, 2023 at 03:51:23PM +0100, Michael wrote:
> i have multiple nullclients with the exact (!) same main.cf. all but one
> show the received header as expected, e.g.:
>
> Received: from host.domain.tld (host.domain.tld [10.0.0.1])
This added by the mailhub host when it receives mail from the
nullclient. The first name is the EHLO name sent by the client,
the second is the FCrDNS name of the IP address as seen by the
receiving mailhub.
> but there is one single host, which doesn't:
>
> Received: from host.domain.tld (host1 [10.0.0.2])
The IP address "10.0.0.2" of this client must be present under an
unqualified name in the /etc/hosts file on the mailhub. IP->name (and
confirmation name->IP) lookups are via getaddrinfo(3) and
getnameinfo(3), i.e. whatever you have configured in nsswitch.conf.
Typically, /etc/hosts is first in nsswitch.conf, and then DNS. You can
remove the "special" nullclient from the mailhub's /etc/hosts, or make
sure the name in /etc/hosts is fully qualified:
10.0.0.2 host.someorg.example host
--
Viktor.
