Protonmail is a free, secure, email service offering end-to-end encryption, zero access to user data, and open source AES, RSA and OpenPGP cryptography, meaning anyone can check their code.

Protonmail is also the world’s most versatile encrypted email service, supporting PGP encryption of Facebook notifications, and easy-to-use encryption for email clients such as Outlook, Thunderbird and Apple Mail.

Protonmail includes an encrypted contacts manager with digital signature verification, encrypted email for Android and iOS through their mobile app, and state-of-the-art protection against DDoS (distributed denial of service) attacks.

For organisations, Protonmail meets HIPAA’s privacy and security requirements, and their service level agreement (SLA) guarantees 99.95% uptime or better – or a partial refund.

Launched to the public in 2014, Protonmail was founded by a team of CERN scientists, engineers and developers “with deep mathematical and technical knowledge” drawn together by “a shared vision of protecting civil liberties online”.

Based in Switzerland, their goal is “to build an internet that respects privacy and is secure against cyberattacks” and their aim is to build “the encrypted communication technologies of the future”. In 2018 they passed an independent security audit in which “no major issues were discovered”.

Protonmail is more versatile but more expensive than Tutanota.

Protonmail provides 500 MB storage free with paid upgrades starting at €5 per month.