We have noticed if the Gmail account has been deployed using Miradore's "Email (Samsung)" configuration profile to the Samsung device, there is an error in the device's end after the password has been inserted: "Unable to upgrade account".
The reason for this error is related to Google's policy. Google is recognizing Samsung's Mail app as a "Less secure app". See the screenshot from the email message from Google with title "Review blocked sign-in attempt":
Basically you have to follow the link "You can continue to use this app by allowing access to less secure apps, but this may leave your account vulnerable." There you can allow access to less secure apps:
When you have granted the access to less secure apps, re-deploy the "Email (Samsung)" configuration profile and the Gmail account setup should work properly.
- Jarkko / Miradore Online Support