[InsideOutSanta]

FWIW, Proton has no billionnaires, crazy or otherwise. They are governed by a non-profit foundation, though:

https://proton.me/blog/proton-non-profit-foundation

I do agree that self-hosting is best, but particularly for email, that's not trivial.

[Over2Chars]

Supposedly these "no code" sites can stand up a basic infra with very little effort.

If so, have a no code site set up a mail host. It might still not be trivial but it might be much easier?