On January 19, 2017, Proton Mail announced a Tor onion site. With a new interface for the web client, version 3.0 also included the public launch of Proton Mail's iOS and Android beta applications. On 17 March 2016, Proton Mail released major version 3.0, which saw the official launch of Proton Mail out of beta. On 14 August 2015, Proton Mail released major version 2.0, which included a rewritten codebase for its web interface. On March 18, 2015, Proton Mail received US$2 million from the non-profit Fondation Genevoise pour l'Innovation Technologique (FONGIT) and Charles River Ventures, although by 2022, the company no longer had venture capital investors. The restrictions were lifted the following day. PayPal stated that the account was frozen due to doubts of the legality of encryption, statements that opponents said were unfounded. During the campaign, PayPal froze Proton Mail's PayPal account, thereby preventing the withdrawal of US$251,721 worth of donations. Two months later, Proton Mail received US$550,377 from 10,576 donors through a crowdfunding campaign on Indiegogo, while aiming for US$100,000. It was met with enough response that after three days they needed to temporarily suspend beta signups to expand server capacity.

On May 16, 2014, Proton Mail entered into public beta. Acquiring no fewer than 2 million users by 2017, membership grew to almost 70 million by 2022. Initial membership was by invitation only however, beginning in March 2016, Proton Mail was opened to the public. Although the default account setup is free, the service is sustained by optional paid services. Proton Mail received initial funding through a crowdfunding campaign. The company also operates Proton VPN, Proton Drive and Proton Calendar. Proton Mail is run by Proton AG (formerly Proton Technologies), which is based in the Canton of Geneva. The service can be accessed through a webmail client, the Tor network, or dedicated iOS and Android apps. 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.

Proton Mail (previously written as ProtonMail) is an end-to-end encrypted email service founded in 2013 in Geneva, Switzerland. protonmailrmez3lotcci pshtkleegetolb73fuirg j7r4o4vfu7ozyd.onion ( Accessing link help).

Proton email service