Our verdict: The Proton Mail desktop app is a clean, separate window for Proton's encrypted email and calendar, with the same features as the web app. The catch is the price: the email account itself can be free, but the Windows app only works on paid plans after a 14-day trial. Free users can keep using Proton Mail in the browser.
About Proton Mail
Proton Mail is developed by Proton AG in Geneva, Switzerland. Messages between Proton users are end-to-end encrypted, and stored mail is protected with zero-access encryption, so Proton cannot read it. All Proton Mail apps are open source under the GNU GPL v3 and have been audited by independent experts.
The Windows desktop app combines Proton Mail and Proton Calendar, with contacts in a side panel, and needs Windows 10 or later. Anyone on a paid or trial plan can use it; free accounts get a 14-day desktop trial. The cheapest plan that includes it is Mail Plus at $3.99 a month billed annually ($47.88), with 15 GB storage, 10 addresses and a custom domain. After the trial, a free account keeps working in the web and mobile apps, but not in the desktop app.
What it does well
- End-to-end encryption. Email between Proton users and to password-protected recipients is encrypted on your device.
- Zero-access storage. Stored mail is encrypted so Proton itself cannot read it.
- Mail and calendar together. Proton Calendar and Contacts are built into the same desktop window.
- Easy Switch import. Imports mail and folders from Gmail, Outlook and Yahoo in the background.
- Clear app data. Clear the local cache from the menu or remove all traces with the included uninstaller.
Who it is for
Good fit
Proton Mail subscribers who want their encrypted inbox and calendar in a dedicated Windows app.
Look elsewhere
Free Proton users who do not want to pay; after the trial they must use the web app instead.
Pros and cons
Pros
- End-to-end and zero-access encryption
- Mail, calendar and contacts in one app
- Open source and independently audited
- Same features as the web app
Cons
- Desktop app needs a paid plan after a 14-day trial (Mail Plus from $3.99/month, billed annually)
- Free plan has only 1 GB of storage
- Encryption to non-Proton recipients needs extra steps
How to install Proton Mail
The button downloads the official Windows installer from proton.me. Sign in with your Proton account; on a free plan this starts the 14-day desktop trial. On a shared PC, sign out after use or clear app data from the Proton Mail menu.
Questions about Proton Mail
Is Proton Mail free?
The email account can be free, with 1 GB of storage and one address. The Windows desktop app, however, needs a paid plan: free accounts get a 14-day trial, after which you need Mail Plus ($3.99 a month billed annually) or higher, or you keep using the free web app.
Is the Proton Mail desktop app different from the web app?
No. Proton says both offer the same Proton Mail and Calendar features and protections, and they stay in sync.
Can I use Proton Mail with Outlook or Thunderbird instead?
Yes, with Proton Mail Bridge, which is available on paid Proton plans.
