Kindly note that we have two apps, and you need to log in to the correct one based on your account type.

If you are a Rediffmail user, use: https://play.google.com/store/apps/details?id=com.rediff.mail.and

If you are a Rediffmail Business user (yourname@company), use: https://play.google.com/store/apps/details?id=com.rediff.entmail.and