ProtonMail Mobile App Troubleshooting Guide

If you are having trouble with your ProtonMail mobile app, please try the following debugging steps to fix the app.

1. If you run into issues, try logging out and logging back in. Closing and re-opening the app may also work.

ProtonMail mobile app menu buttonProtonMail app Sign Out button

2. If issues persist, try clearing the local data cache. This can be down through the settings page as shown below.

ProtonMail app Settings buttonProtonMail app Refresh Local Cache

3. As a last resort, you can uninstall and re-install the application.

4. If you continue to experience issues, please use the report bug feature in the application as described in this link:

5. If you cannot use the report bug feature, get in touch with us via this link Please include the following information:

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  1. Lane Moore

    I was able to install the new beta app on my tablet running stock android but not on my rooted phone running a number of customizations. After multiple attempts I was not able to install the new beta using the Crashlytics app so I did some research and found some posts on Stack Overflow that solved my issue. It turns out that the Crashlytics app will not install on a device that has a screen dimmer app or an ad blocker. I had both! I use Adgard to block ads and f.lux to adjust my screen brightness. Disabling those allowed me to install the new beta. I think it would be a good idea to add notes on this to the troubleshooting guide.

  2. Paul

    I cant login to my android Protonmail after setting up a pc account. It says Unknown or incorrect username or password when I know its 100% correct

  3. ProtonMail Support

    Can you please contact us at

  4. ProtonMail Support

    Sorry to hear that. Can you please contact us at

  5. Chris

    I keep getting that my message is rejected by the server. Why?

  6. ProtonMail Support

    Please contact us on or via the report bug button for assistance.

  7. SC

    I am not able to log into IOS app – it repeatedly states “Authentication Failed Wrong username or password” however I am certain that I am using correct UN and pW

  8. ProtonMail Support

    Can you please send the details to

  9. william

    can i change how often protonmail app on android checks for mail or is it set to constantly keep checking

  10. ProtonMail Support

    At this moment it is not possible to do this. We will look into it, and check if the feature can be added in the future.

  11. william

    thanks most email apps have that feature so it would be nice

  12. M. Robinson

    Where are the attachments being downloaded to?

  13. ProtonMail Support

    You will probably find the downloaded attachments in the Download folder.

  14. protonuser432

    I’m noticing that if I log into my account online, I see 20 or so archived messages – but on the app, it only shows 3 messages? Anyone else having this problem? I’ve logged in/out.. killed the app, reinstalled it, etc, etc. and it keeps showing the same behavior. I’m on ios 9.3.5 and protonmail version 1.5.3 (1702)

  15. ProtonMail Support

    This will be fixed in the next release of the mobile app.

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