On 07/04/2019 20:14, Chris Green wrote:
> ...
>
> The machine on which postfix runs is called esprimo and thus, within
> my LAN, its name is esprimo.zbmc.eu. However the above seems to mean
> that mail sent outside gets the name esprimo.zbmc.eu in its headers
> and that seems to have provoked some errors recently, prsumably
> because esprimo.zbmc.eu doesn't exist in the outside world.
>
> ...
It's not clear what is the issue you are seeing and whether it is an
issue with your smarthost or another server.
I would recommend you to set your public dns so that esprimo.zbmc.eu
resolves to the public ip of your router. For completeness you might
also want to point your MX record at that hostname too. You can still
use the private ip for esprimo.zbmc.eu on your local LAN by overriding
the public dns with something like /etc/hosts or a local dns server.
Looking at the headers from your email to the list:
Received: from esprimo.zbmc.eu (unknown [84.92.49.234])
(Authenticated sender: catch...@isbd.net)
by outmx-028.london.gridhost.co.uk (Postfix) with ESMTPA id
B59BC20A68F29
for <postfix-users@postfix.org>; Sun, 7 Apr 2019 19:14:18 +0100 (BST)
Received: by esprimo.zbmc.eu (Postfix, from userid 1000)
id 8A147560AE6; Sun, 7 Apr 2019 19:14:18 +0100 (BST)
In the first header esprimo.zbmc.eu comes from the helo/ehlo name
provded by your server, that is defined in the parameter smtp_helo_name,
default value $myhostname.
The ip 84.92.49.234 is the one being used to connect to the smarthost.
The fact that there is an "unknown" indicates one of these:
1) that a reverse lookup of 84.92.49.234 failed (for me it resolves)
2) that the forward lookup of the reverse name failed (for me it resolves)
3) the ip from the forward lookup does not match 84.92.49.234 (for me it
matched)
4) the smarthost server has smtpd_peername_lookup set to no in it's
configuration.
John
