ProtonMail

ProtonMail is an end-to-end encrypted email service founded in 2013 in Geneva, Switzerland by scientists who spent time at the CERN research facility. ProtonMail uses client-side encryption to protect email content and user data before they are sent to ProtonMail servers, unlike other common email providers such as Gmail and Outlook.com. The service can be accessed through a webmail client, the Tor network, or dedicated iOS and Android apps.