postfix on Ubuntu 22.04 and ISPConfig 3.2.11p1 not resolving domains in hosts file

Hello everyone,
It is been a while I am using ISPConfig, started on ubuntu 18.04 till now.
I will make it short, in my setup i have several mailservers inside my network on different vlans, each has its own public IP but all have the same router/firewall, usually i add the mailservers address which is the exact address of the mx record that is published publically and i point it to the internal IP of the server so no internet connection required between the servers.
few days ago i installed a new server for ISPConfig using the autoinstaller in latest post here and i noticed the server is not even trying to communicate with other servers using the internal IP provided in the hosts file. I searched a lot on the internet but none was helpful.
i hope someone here can guide me through to solve this issue.

 

ISPConfig autoinstaller does not set up network settings. You should set up subnet, router and netmask before installing ISPConfig.
Can you ping the host from the other hosts in the subnet and vice versa?

 

Ofcaurse, I have configured all before installing, i can even telnet to those servers on 25 from the server cli. also, if i use the hostname that i configured in hosts file, the telnet goes to the correct ip. only postfix doesn't.

 

I agree the same, I believe the issue relies in Postfix.

the error from mail log

and hosts file

 

Hey @till,
thank you. in my trouble shoot before i open the ticket i reached this site and i added smtp_host_lookup=native which it didn't work. now i read it more carefully it appeared that i have to add lmtp_host_lookup=native as well. all seems to work now

below postfix configs