Overall, it’s an impressive level of security for emails. You can enable two-factor authentication (opens in new tab) so no one can access your account without also having access to your mobile device. There’s full support for PGP, and the encryption algorithms used are open-source versions of RSA and AES. The code for the web client and encryption algorithms are all open-source (opens in new tab), so any security issues can be patched quickly. In terms of physical security, ProtonMail’s IT infrastructure (opens in new tab) resides under 1,000 meters of granite rock and your data never goes to the cloud. However, the email subject lines are not stored in an encrypted format, so if compelled to by a Swiss court order, ProtonMail could turn over the subject of your emails to the authorities. ProtonMail uses end-to-end, zero-access encryption for your emails, so they are always encrypted when in transit or when stored on the email servers. ProtonMail has a comprehensive knowledge base (Image credit: ProtonMail) ProtonMail: Security

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