Resolved Email rejected: HELO domain does not resolve

[LMAR6]

Hi!

I new help reconfiguring Postfix because a specific mailfilter doesn't accept mails from our server.

Plesk Version: Version 17.5.3 Update #7
Hostname: server.my-host.com (example, rDNS is set)
HELO domain: server.localdomain
Outgoing mail mode: Send from domain IP addresses

Error

host abc.dfe.com[xx.xxx.xxx.xx] said: 554 5.7.1
    <server.localdomain>: Helo command rejected: HELO domain does not resolve
    to you (in reply to RCPT TO command)

Why does Postfix use server.localdomain? I thought "The host name used in the SMTP greeting is the Plesk server host name specified in Tools&Settings > Server Settings", which is server.my-host.com...

Any ideas how to adjust the HELO to server.my-host.com (which should be the correct Helo, shouldn't it)?

Thanks in advance!

Edit: Sorry, noticed I used the wrong forum....

 

[LMAR6]

Nevermind.

I don't no why, but the hostname was not properly set. It was only "server" so I guess Postfix added localdomain, cause it wasn't a fqdn.

The hostname in plesk settings was server.my-host.com (but /etc/hostname only contained server). Updating the hostname wasn't successful (no changes), so I first changed the hostname to something different and after that replaced with the right one and saved. Now /etc/hostname contains server.my-host.com and Postfix also uses this name for Helo. Mailfilter does now accept the mail. Just in case anybody gets the same problem.

 

[Yves Vogl]

I think this is an bug. I had this issue on
CentOS Linux 7.4.1708 (Core)‬
Plesk Onyx 17.5.3 Update #41

It seems to occure when using a hostname with 2 labels only (e.g. example.com) and preconfigured the server correctly so that "$ hostname" echoes "example" and "$ hostname -f" echoes example.com.