Google no longer allows apps to sign you in inside their own built-in browser window. When you add a Gmail account, BlueMail hands the sign-in over to a real browser on your device, so you need a supported one installed and working, or the sign-in fails.
Browsers That Work
Android: Chrome, Samsung Internet, Firefox, Microsoft Edge, Brave, Opera.
iOS and iPadOS: Safari, Chrome, Firefox, Edge. Safari is present on every device, so sign-in normally works out of the box.
Windows, Mac and Linux: Chrome, Microsoft Edge, Firefox, Safari (Mac), Opera, Brave, Vivaldi.
Any current, mainstream browser is fine. The requirement is not a specific brand, it's a full browser that Google accepts and that can complete the OAuth flow.
What Causes the Error
- An embedded or in-app browser. Google deliberately blocks sign-in inside webviews embedded in other apps, because they can't be verified as a genuine browser. This is the most common cause of the error.
- An out-of-date browser. Old builds fail Google's checks. Update your browser and try again.
- A stripped-down or privacy-focused browser. Firefox Focus, Tor Browser, and similar tools clear state aggressively or block scripts that the sign-in needs, which can interrupt the flow partway through.
- Strict blocking settings. Blocking all cookies, all JavaScript, or all cross-site requests will stop the sign-in. Allow them for
accounts.google.comwhile you add the account. - No default browser set. If your device has no default browser, BlueMail has nowhere to send the sign-in. See how to set a default app for where these settings live.
If Sign-In Still Fails
Set one of the browsers above as your device's default, update it, and try adding the account again. If you use a privacy browser day to day, switching the default temporarily just for the sign-in is usually enough, BlueMail only needs the browser during setup.
You can also read more about how OAuth sign-in works and adding a Gmail account.
