Meanwhile I was able to dig for the root cause togetrher with ["johannes"] and found:
my mail provider (GMX) refuses to accept the mail from the forum's mail-server. The reason seems to be that here in Germany at least GMX and WEB.de perform a "reverse DNS lookup" (https://en.wikipedia.org/wiki/Reverse_DNS_lookup) for the delivering server to reduce spam load (and in fact it is efficient). The forum server logs following:
I have checked the header of such a mail which carries a local IP address for the sender of forum mail.Jul 24 08:30:37 public postfix/smtp[25457]: 9226E9868D: host
mx00.gmx.net[213.165.67.99] refused to talk to me: 554-gmx.net (mxgmx010)
Nemesis ESMTP Service not available 554-No SMTP service 554 invalid DNS
PTR resource record
I digged out an old notification from May 2012 where Exito's mail server
was different and all worked fine. Here the important part form that
mail-header:
.... snip ....
Received: (qmail invoked by alias); 08 May 2012 07:35:54 -0000
Received: from mail.excito.net (EHLO excitohb.cust.ipeer.se)
[213.180.84.211]
by mx0.gmx.net (mx025) with SMTP; 08 May 2012 09:35:54 +0200
Received: from excitohb.cust.ipeer.se (localhost.localdomain [127.0.0.1])
by excitohb.cust.ipeer.se (Postfix) with ESMTP id 12A4C3A21624
for <ingo-xyz@gmx.net>; Tue, 8 May 2012 09:35:52 +0200 (CEST)
Subject:
...... snip ........
And now you can clearly see the sender is:
"mail.excito.net" with IP = 213.180.84.211.
Checking the reverse DNS lookup:
Code: Select all
dig PTR -x 213.180.84.211
So at that time all was fine and now it fails because of 2 things:
1. forum's mail server has a private/local IP address
2. IP and hostname do not match and cannot be reverse resolved.
So I wonder if I (with GMX and/or WEB.de as mail provider) am the only one not receiving mails from the forum anymore???
This can only be solved by Exito by delivering the mails though an officially approved mail server.
Best regards,
Ingo