If you are at all concerned about the growing threat to online security, consider Proton Mail.
I’ve been using their secure, Swiss-based email system for a couple of months now to communicate with a security-conscious friend and have enjoyed it. It’s free online and easy to use.
The interface feels quite like Gmail – intuitive, clean, and simple, but with a sober blue color pallette. The messages are automatically encrypted. You can set up Proton to notify you at your primary email address when you have new messages so you don’t really have to check two addresses, which is one of my principles in keeping your inbox clear.
The encryption is not quite as safe as, say, PGP but it’s a heck of a lot quicker.
Give it a look.