In Gmail, notifications of new emails are indicated by a read unread email icon. When you have no new emails, there is no unread number. If you are facing the issue of Gmail notifications not working and are unable to see notifications for new emails, try these steps 1) Go to Settings>Labs>Enable New Mail Notifications. 2) Go to Settings> Labs> Enable Display New Mail Icon and Always choose Top. 3) Now, you can go back into settings and change notification settings for each account individually. If you have multiple accounts, ensure notifications are turned on for all of them.