Proton Mail Bridge(new window) is an application that seamlessly encrypts and decrypts your mail as it enters and leaves your computer.
It allows you to fully integrate your Proton Mail account with a third-party client that supports IMAP and SMTP protocols, such as Microsoft Outlook, Mozilla Thunderbird, and Apple Mail. This includes support for importing emails into your Proton Mail account from other email accounts that are connected to the same client, as well as full-text search of your Proton Mail emails from within your client.
You can find Proton Mail Bridge for macOS, Windows, and Linux on the Proton Mail Bridge homepage(new window), along with frequently asked questions and detailed setup instructions for each of the supported clients.
Proton Mail Bridge is currently available only if you have a paid Proton Mail plan. However, this may change in the future to include our Proton Free plan as we develop our infrastructure.