i'm just testing this new how to (choosing ubuntu 20.04 lts... perhaps deb11 is better ???) : https://www.howtoforge.com/ispconfig-autoinstall-debian-ubuntu i need , at the begining, just panel and mail server features. i think a good idea is to have a reverse dns with : mail.mydomain.fr pointing to my ipv4 public ip. But i see that you setup your hostname to "server1" Do you see any problem in changing this with adding to /etc/hosts : 127.0.1.1 server1.mydomain.fr server1 mail.mydomain.fr ?
I personally prefer Debian. You should use the same hostname for the rDNS record as the hostname of your server. So either server1 or mail. Personally I give them unique names which are used for sending out, but they can be reached by others on mx1.example.com / smtp.example.com / imap.example.com.
thank you thom. i will re install with a debian 11, then choose mail.mydomain.fr according to your advice.
