Proton Mail Not Working? Fixes for Sign-In, Apps, Bridge and Missing Mail

Proton Mail problems usually come from one of five places: signing in, the mobile app, Proton Mail Bridge (for desktop email apps), the free plan's limits, or a website that won't accept your address. Jump to the one that matches.

You can't sign in

• Check what you typed with the eye icon, Caps Lock, and spaces in a pasted password.
• Accounts created with a non-Proton address must sign in with that full address.
• Two-factor code rejected? Set your phone's date and time to automatic.
• Try a private browser window, clear cookies and cache, or use the Proton app.
• Account locked for security reasons? Verify and change your password straight away.

Full checklist: signing in to Proton Mail. Forgotten password: resetting it without losing your emails.

The iPhone or Android app misbehaves

Proton's own order of fixes:

1. Update the app from the App Store or Google Play.
2. Close and reopen it.
3. Sign out and back in.
4. Remove the app and install it again.
5. Still broken? Use Report bug in the app, or contact Proton with your device, OS version and app version.

Outlook, Apple Mail or Thunderbird stopped receiving (Bridge)

Desktop apps reach Proton through Proton Mail Bridge on your computer, so most problems start there:

1. Restart Bridge, then the email app. Check that Bridge shows the account as connected, with no connection errors.
2. Test another email app. If a second app also gets nothing, the problem is Bridge; if it works, the problem is the first app.
3. Check more often: set the app to check for new mail every minute.
4. Fix app-specific errors:
   • Outlook “Cannot connect to server”: make sure Bridge is running, then compare the server settings in Outlook with those shown in Bridge.
   • Thunderbird “Could not connect to mail server 127.0.0.1”: confirm Bridge is running and the server and port match Bridge.
   • Apple Mail “Unable to verify”: copy the password from Bridge and enter it again.
5. Repair Bridge: in Bridge, go to Settings › Advanced and choose Repair Bridge to resynchronise. If messages still don't appear, back up and re-add the account in the email app.

The email app uses the username and password that Bridge generates, not your Proton password. Setup details: Proton Mail server settings. Bridge needs a paid plan.

You've hit a free-plan limit

• Storage: the free plan starts with 500 MB of mail storage, rising to 1 GB once you finish Proton's getting-started steps. Your usage shows at the bottom left of the web app. Delete large messages or upgrade if you're close to full.
• Sending: free accounts can send up to 150 messages a day.
• Desktop apps and custom domains: not available on the free plan — they come with Proton Mail Plus.

A website won't accept your Proton address

Some sites block sign-ups from Proton addresses. Contact Proton support (it asks companies to lift these blocks) or write to the company yourself. With a paid plan, a @pm.me address or your own domain usually gets through.