[Users] HELO/EHLO hostname gathering

[Slavko]

Dňa 21. septembra 2024 10:46:31 UTC používateľ Marco Moock <mm at dorfdsl.de> napísal:

>-rw-r--r-- 1 root root 15 10. Dez 2023  /etc/hostname

While i have no link/source of that, IIRC the hostname have
not to be FQDN, as hostname characters are limited to a-z
and dash (no dot for FQDN).

If you set FQDN as hostname, it can seems as working, but
you can check that this is wrong by commands:

    hostname
    hostname -f
    hostname -d

The first have to return hostname, second FQDN and third the
domain suffix.

AFAIK, the way to get it works is to make hostname resolvable
via DNS (with domain part from /etc/resolver) or more simple,
create alias in /etc/hosts (FQDN first):

    127.0.1.1 hostname.example.com hostname

I don't know how CM gets FQDN, but IMO, it is possible that
from system and if resolving FQDN (syscall) fails, CM uses
some default value.

BTW, the domain part of MID header is not required to be valid
FQDN, it servers only ID purpose and has only local mean. Be
free to setup (near to) anything in CM settings. In regards of
SPAM filtering, it is best to use FQDN syntax (some antiSPAMs
can penalize that).

regards


-- 
Slavko
https://www.slavino.sk/