The only way to run a forum unless it has little traffic is on a
CentMinMod CentOS7 Server (VPS or Dedicated)
in my humble opinion.....
By forum I mean XenForo, vB, Invision or other....
As for difficulty, after running cPanel servers for many years and having various bits fall over with updates, Contacting cPanel with support tickets, CMM is far far easier with less hiccups and the support is far superior, combine that with a decent VPS provider (I use Vultr and Hetzner) with snapshots and automated backups and the ability to clone a server to another, its really the only way... The other thing is the cost of cPanel which has escalated in recent years astronomically when they got taken over...
And by far the best way to run the email server (
again in my humble opnion after many years) is to offload this from your forum server and either outsource it (No point me listing them when CMM has a list
here ) - My personal choice that I use is Namecheaps PrivateMail paid for facility which works out pretty cheap or run a cPanel server for the emails.
The beauty of a separate server for the emails is is the forum goes down or is taken offline the mail still works and vice versa...
Letsencrypt SSL is a breeze to set up and use on CMM.....
And Nginx is a totally great web server, after coming from 15 years of Apache it was fairly easy to pick up...
I had to buy a license just to be able to make this post