I can agree with everyone here, self hosting mail at this point is pointless. You are going to spend so much of your time reaching out to be pulled off of blacklists only to be added right back onto another. It’s a vicious cycle unfortunately, and than just wait until you get added to Barracudas or Proofpoints naughty list… you may as well start over at that point.
I use EndeavourOS, Gnome on my desktop and KDE on my laptops. I really like the AUR and the integration with yay. Started with Ubuntu about 7 years ago and had always used Debian based distros, moved to Arch when I wanted to learn more about Linux and now I use EndeavourOS as my daily driver.
On my servers I use a mic between Debian 11 and 12