Proton Mail adds a bitcoin wallet. Yes, really.

https://awful.systems/post/1981275

Proton Mail adds a bitcoin wallet. Yes, really. - awful.systems

Proton better not go downhill I can’t be changing addresses willy nilly.
If you’re willing, I strongly recommend people get their own domains. That way, you’ll always be able to change email providers without changing your address.
Setting up email and actually getting into people’s mailbox isn’t trivial.
If you self host? Absolutely. That’s a nightmare. Paying a provider (like proton, for instance) to host and manage your email is easy. I haven’t run into any issues having my email accepted, even by hotmail addresses.