ProdigalFrog

The biggest advantage of private email is that it stops the email provider itself from data mining some of your most sensitive info, as Gmail and other free emails most certainly do. Basically it’s protection from surveillance capitalism, but you rightfully can’t consider it a secure way to send messages or info to other, non-encrypted users.

Posteo is only 12€ a year, so a bit cheaper. Doesn’t support custom domains though.

Sounds like that’ll generate an untold amount of ewaste.