[flyinghamster]

I'd never recommend Fedora, non-LTS Ubuntu, or Debian Unstable for a Linux newcomer. Any time you run a development release, you risk breaking something whenever you update.

I've been happy running Cinnamon on Ubuntu LTS releases, and I like what I see playing with KDE as well. I've never had a kernel fail to boot (other than by hardware failure), and AppArmor is, IMO, far better at staying out of the way than SELinux. I can't help on the Exchange stuff, I've never had to deal with that.

It would be a little easier to just run Mint instead (Cinnamon being native there), but on Ubuntu you can just "apt install cinnamon-desktop-environment" and then choose Cinnamon the next time you log in.