SMTP postfix mail bounced host or domain name not found

Hi i am new at this and i am trying to use telnet to send myself but i cant receive the mail because i get this problem i am using 2 machines with debian 10.9 one has dns and dhcp(172.16.1.1) and other has postfix (172.16.1.6) here is my postfix conf i just want to send to myself an mail. I just want to send a mail to myself using telnet and be able to see it in /var/spool/mail thanks in advance for the help

It looks like that Postfix is trying to send the message to asir.lan and gets stuck forever as he can't find the address of asir.lan webserver:

Name service error for name:asir.lan type:A

So why is it sending the email to asir.lan instead of processing it on its own? Most probably because it does not understand that it is actually responsible for the email zone of asir.lan.

I'm not a big Postfix guy, but my guess would be that the issue is in mydestination variable. In your configuration it's referring to "mail.asir.lan"; try to add just "asir.lan" there, e.g.

 mydestination = $myhostname asir.lan mail.asir.lan localhost.asir.lan localhost

Also, I would suggest looking at /etc/mailname and make sure it's containing "asir.lan" in it.

Do refer a standard configuration example if needed: http://www.postfix.org/STANDARD_CONFIGURATION_README.html