This is not a plugin issue, please try one of the followings steps:
- If you’ve turned on 2-Step Verification for your account, you might need to enter an App password instead of your regular password.
- Sign in to your account from the web version of Gmail at https://mail.google.com. Once you’re signed in, try signing in
to the mail app again.
- Visit http://www.google.com/accounts/DisplayUnlockCaptcha and sign in with your Gmail username and password. If asked, enter the
letters in the distorted picture.
- Your app might not support the latest security standards. Try changing a few settings to allow less secure apps access to your account.
- Make sure your mail app isn’t set to check for new email too often. If your mail app checks for new messages more than once every 10
minutes, the app’s access to your account could be blocked.