hostname as part of sender address for PMG messages

[LostInTranslation]

Hello,

first I'd like to excuse myself: I did see discussions about this issue here also, but I can't find them any more and the issue is still not solved for me.

I'm struggling with messages sent by the PMG itself. Sender in my case is postmaster@myhostname.my-domain.com. Problem is, that my mail server is rejecting these mails:

2024-03-19T06:40:00.501094+01:00 tgspmg postfix/smtp[2909444]: 3CD0D2F7DA: to=<jhe@my-domain.com>, relay=10.32.1.10[10.32.1.10]:25, delay=63450, delays=63450/0.08/0.17/0.06, dsn=4.1.8, status=deferred (host 10.32.1.10[10.32.1.10] said: 450 4.1.8 <postmaster@myhostname.my-domain.com>: Sender address rejected: Domain not found (in reply to RCPT TO command))

myhostname and my-domain.com were changed due to anonymization.

The problem is: the mail server would accept mails from postmaster@my-domain.com, but does not know anything about a mail domain myhostname.my-domain.com.

I did already check, if setting "Administrator EMail" (Configuration: System) helps, but it does not.

Any advice?

Thanks a lot!
Jens

 

[Stoiko Ivanov]

Sender address rejected: Domain not found (in reply to RCPT TO command))

This is most likely due to a missing reverse (or forward) DNS entry for myhostname.my-domain.com pointing to your PMG's IP address - in your internal DNS
Either add those entries, or add your PMG's IP-Address to the trusted relays of your downstream server (10.31.1.10)

I hope this helps!

else to see how the hostname of PMG is constructed see:
https://pmg.proxmox.com/pmg-docs/pmg-admin-guide.html#_configuration_files_overview