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

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

What’s the problem with this?

If they can moderate that many groups to the standard each community is happy with is it an issue?

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.

Lemmy is opensource, you can see and get a copy of the source code here. https://github.com/LemmyNet/lemmy There’s no development cost because all developers are volunteers at this stage.

For each instance that depends on the admins running that individual instance. The instance I use is being sponsored by a NZ company that are providing the admin’s a free virtual server to host on.