To customize push notifications:

1. Open the Zoho Mail mobile app.

2. Tap the Hamburger icon in the top-left corner of the app.

3. Tap the Settings icon.

4. In the User Account section, tap on your account.

5. Enable Push Notifications for your account.

6. Open Folder-based Notifications and select the folders for which you want to receive notifications.

7. Open Sender-based Notifications and select the contacts for whom you want to receive notifications. 
   

If the Push Notifications setting is unavailable in the User Account section, notifications might be disabled in your device’s settings. You can follow the steps outlined in this article to enable notifications for the Zoho Mail mobile app.