End-to-end encrypted email service
Proton Mail Screenshot of the Proton Mail website, showing the conversation view of a message in a user's inbox
Available in
English ,
Catalan ,
Chinese ,
Dutch ,
French ,
German ,
Hungarian ,
Italian ,
Japanese ,
Polish ,
Romanian ,
Russian ,
Spanish ,
Turkish ,
Portuguese ,
Ukrainian
Headquarters Owner Proton AG URL proton .me /mail Commercial No Registration Required Users 100 million (April 2023)[ 2] Launched May 16, 2014; 10 years ago (2014-05-16 ) Current status Online
Proton Mail (previously written as ProtonMail ) is a Swiss end-to-end encrypted email service founded in 2013 headquartered in Plan-les-Ouates , Switzerland .[ 7] [ 8] Proton Mail is now run by Proton AG , which also operates Proton VPN , Proton Drive , Proton Calendar , Proton Pass and Proton Wallet. It uses client-side encryption to protect email content and user data before they are sent to Proton Mail servers, unlike other common email providers such as Gmail and Outlook.com .[ 9] [ 10]
Proton Mail received its initial funding through a crowdfunding campaign, and initial membership was by invitation only; however, beginning in March 2016, Proton Mail was opened to the public. Acquiring more than two million users by 2017,[ 11] membership grew to almost 70 million by 2022.[ 12]
The source code for the back-end of Proton Mail remains closed source.[ 13] [ 14] However, Proton Mail released the source code for the web interface, iOS and Android apps as well the Proton Mail Bridge app, under an open-source license .[ 15] [ 16] [ 17] [ 18]
^ "Privacy policy" . Archived from the original on September 5, 2021. Retrieved May 28, 2022 .
^ Yen (April 18, 2023). "There are now over 100 million Proton Accounts" . proton.me . Archived from the original on April 18, 2023. Retrieved December 18, 2023 .
^ "iOS mobile app repository" . github.com/ProtonMail/ios-mail . Proton AG. Archived from the original on November 1, 2019. Retrieved May 25, 2024 .
^ "Android mobile app repository" . github.com/ProtonMail/android-mail . Proton AG. Archived from the original on May 26, 2024. Retrieved May 25, 2024 .
^ "Proton bridge repository" . github.com/ProtonMail/proton-bridge . Proton AG. Archived from the original on April 17, 2020. Retrieved May 25, 2024 .
^ "LICENSE" . github.com/ProtonMail/WebClient . Proton AG. December 25, 2021. Archived from the original on December 25, 2021. Retrieved May 25, 2024 .
^ O'Luanaigh, Cian (May 23, 2014). "CERN inspires entrepreneurs for email encryption" . CERN . Archived from the original on May 16, 2020. Retrieved May 22, 2020 .
^ "Why Proton Mail is in Switzerland" . Proton . May 19, 2014. Archived from the original on July 6, 2022. Retrieved May 28, 2022 .
^ Saxena, Kumkum; Rajdev, Dev; Bhatia, Divesh; Bahl, Manav (June 25–27, 2021). "ProtonMail: Advance Encryption and Security". 2021 International Conference on Communication information and Computing Technology (ICCICT) . pp. 1–6. doi :10.1109/ICCICT50803.2021.9510041 . ISBN 978-1-6654-0430-3 . S2CID 237000409 .
^ "ProtonMail, the Easy-to-Use Encrypted Email Service, Opens Up to the Public" . March 17, 2016. Archived from the original on July 2, 2016. Retrieved March 18, 2016 .
^ "Fighting Censorship with Proton Mail Encrypted Email Over Tor" . Proton Mail Blog . January 19, 2017. Archived from the original on May 28, 2022. Retrieved January 20, 2017 .
^ Edelman, Gilad (May 25, 2022). "Proton Is Trying to Become Google—Without Your Data" . Wired . ISSN 1059-1028 . Archived from the original on September 30, 2023. Retrieved May 27, 2022 .
^ Proton Mail [@Protonmail] (September 25, 2020). "@TheEvanCarroll That is correct. We don't have a stand-alone back-end that can be installed for small deployment, because our backend software is optimized for large deployments with millions of users and distributed infrastructure" (Tweet ). Archived from the original on July 10, 2021. Retrieved September 11, 2021 – via Twitter .
^ "Proton Mail responds on Reddit" . April 2, 2019. Archived from the original on November 14, 2020. Retrieved September 24, 2020 . We don't plan to open source the back-end code, because it doesn't add trust (users can't verify what code is running on the backend) and doing so would given away information about how we do anti-spam and anti-abuse.
^ "Proton Mail goes Open Source with version 2.0" . Proton Mail Blog . August 13, 2015. Archived from the original on May 28, 2022. Retrieved January 31, 2016 .
^ "Proton Mail iOS app is open source" . Proton Mail Blog . October 30, 2019. Archived from the original on May 28, 2022. Retrieved December 12, 2019 .
^ "The Proton Mail Android app is open source" . Proton Mail Blog . April 23, 2020. Archived from the original on May 28, 2022. Retrieved April 24, 2020 .
^ "Proton Mail Bridge is open source on macOS, Windows, and Linux" . Proton Mail Blog . April 15, 2020. Archived from the original on May 28, 2022. Retrieved April 24, 2020 .