I see you’ve more or less chosen proton.
Came here to say that I have been using tutanota for years now and it works very well.
It does fit the use case of encrypted emails to people who don’t use tutanota. How it works is they will receive an unencrypted email letting them know they have an encrypted email waiting for them, along with a secure link to an https encrypted, password protected web interface with inbox and outbox.
Just wanted to point this out for anyone else evaluating privacy focused email providers.
It’s not too bad. Pretty standard with like anyone who needs to communicate securely like banks and insurance.