Benefits include end to end encryption, anonymity, self destructing messages, SSL secured connection, no logs, no ip address tracking, no back doors, secure user data.
https://protonmail.com/
More info on proton mail security: https://protonmail.com/security-details
Why Switzerland: https://protonmail.com/blog/switzerland/
How to encrypt messages sent to non-proton users (gmail, yahoo, hotmail, etc) https://protonmail.com/support/knowledge-base/encrypt-for-outside-users/
