Protonmail Windows App Guide

For threat models where the adversary controls browser extensions or where the user desires offline access without leaving a browser tab open, the Windows app is a clear upgrade. For users with extreme paranoia (air-gapped machines, Qubes OS), the web client in a disposable VM remains superior.

Critical to the desktop app is that all decryption must occur on the client device. Thus, the Windows app must manage private keys and decrypted plaintext temporarily. protonmail windows app

The app implements:

If you search the Microsoft Store, you may find third-party apps claiming to be ProtonMail clients. ProtonMail is open source, but unofficial apps in the store could potentially compromise your privacy or security. Always verify that the developer is "Proton AG" or stick to the official web interface and Bridge. For threat models where the adversary controls browser