The ProtonMail Android app is supposed to be a privacy-centered alternative for data-mined email services such as Gmail, Yahoo, and Outlook. If this is truly the case, why does the Android app require Identity permissions which allow the app to view existing accounts on the device?
You can find more details on the link below for the permissions ProtonMail Android app is using, along with information why each of them is needed.
Identity: Allows push notifications when you receive new messages through the ProtonMail app. Unfortunately this is the only solution to provide push notifications at this time. We will continue to look for alternate solutions.
As this page says: https://support.google.com/googleplay/answer/6014972?hl=en identity is mainly used to get your "contact card" which is obviously useful if the application want to automatically fill signature or sender friendly name.
By following the link guideline to check the authorization:
Using the Settings app on your device (for apps you've already downloaded)
On your device, open your main Settings app. Select Apps or Application Manager (depending on your device, this may be different). Select an app. Scroll down to "Permissions."
I just see "Contacts" and "Storage".
So maybe this permission was set mandatory but not used for the main behavior of the app (especially if you still have an account))
I'm using a custom version of android (exodus) which prompt me when an app is claiming an access (instead of directly allowing every required access at install). And I was not prompted about identity access (even by performing new account creation with SMS code, etc.)
So, I don't think this identity requirement is dangerous, but unfortunately, I have no confirmation about why protonmail needs it.