Resolved Postfix: mail for postmaster@domain loops back to myself [every other works]

[KNARZ]

I have some weird problem with just the alias "postmaster@domain" any other alias or Mail account (so far I tested) has no issues.

The system is a VPS/Root Server with own Subdomain from the Hoster. This one I use to manage the Server with Plesk and so on. Kind of the generel Hostname as I have several domains on the System. So I'm not using my primary, all day used domain, for the hostname. (if this matters?!)

support@domain or whatever all works fine. Only postmaster@ is not working?!

This being said, this is the interessting part of the mail I receive while testing the postmaster@domain adresse.

Undelivered Mail Returned to Sender

Source of Mail:
The mail system
<root@<sub.hostname>> (expanded from
    <postmaster@<domain>>): mail for
    <sub.hostname> loops back to myself
Diagnostic-Code: X-Postfix; mail for <sub.hostname> loops back to myself

With "sub.hostname" I mean something like: vm10201.somehoster.tld 8443 for plesk)

I kind of suspected my change from the default DNS template from:
Original:

<domain>.    TXT    v=spf1 +a +mx +a:<sub.hostname> -all

Changed to:

<domain>.    TXT    v=spf1 +a +mx +a:<domain> -all

Mx Entry:

<domain>.    MX (10)    mail.<domain>.

All other entries are IPs or refer to <domain> - nothing else to <sub.hostname> [as in the original DNS template]

postconf -d
postfix conf:

mydestination = $myhostname, localhost.$mydomain, localhost
mydomain = <HOSTER-DOMAIN-without-the-subdomain-to-my-server>
myhostname = <sub.hostname>

Can someone help/explain my why postmaster is not working?

 

[Bitpalast]

These addresses are reserved for system use:

• anonymous@...
• drweb@...
• drweb-daemon@...
• kluser@...
• mailer-daemon@...
• mailman@...
• postmaster@...
• root@...

Do not configure mailboxes or own addresses on your domain with them. They won't work the way you expect it.

 

[KNARZ]

Thanks for the info.

But there is one thing than I don't understand.
I had a server running wit 11.5 and migrated to another server with onyx. In 11.5 postmaster@ worked fine. - any explainations to that situation?

 

[AYamshanov]

Just for history: It is possible to customize a set of system aliases starting with Plesk Obsidian 18.0.66.

- (Plesk for Linux) Added the ability to stop accepting mail sent to preconfigured aliases such as root, postmaster, or anonymous on Plesk servers using Postfix or qmail as the mail server. By default, such emails are delivered to the Plesk administrator’s mailbox.
[...]

(c) https://docs.plesk.com/release-notes/obsidian/change-log/#plesk-18066