Just a couple of postfix questions. Thanks in advance for any replies.
Setup: Centos 7 - minimal install on SSD VPS
I noticed, when setting up a second server for DNS and backups that Webmin installs Postfix version 2.6 and my primary server with Virtualmin uses Postfix version 2.10. I re-installed Postfix with yum but the version number remains at version 2.10. Is this something specific to Virtualmin base repo?
After many nights of reading I have come to the conclusion that port 587 is only needed for submission when using email clients such as Thunderbird. As I only use Usermin I presume I only need to open Dovecot ports in my firewall - ports 143 and 993 (email is sending and receiving ok from within Virtualmin).