That's what xmpp is. It was embraced by Google and Facebook and killed.

Email has the same problems as federated lemmy servers.

Mail Servers can end up on distrubuted blacklists and unable to communicate with each other. When office 365 has an outage it causes huge problems because it's a single large provider having issues. That provider goes down but not email as a whole.

This is the same as what happened about a week ago when lemmy.ml and lemmy.world went down due to load.

Best is so subjective.

I am running pivpn, pihole, all the arrs, jellyfin, gitea and rundeck.

I have a home server and a laptop. Both run different versions of Ubuntu