Setting message notifications and message previews.
How to set message notifications
Start the Message app, tap the menu button in the upper right corner of the screen then select “Settings > Notification settings.”
Enable ''Notifications” with a checkmark for generating notification alerts when new messages arrive.
When “Show new message pop-ups” is turned on, a preview of newly received messages can be viewed in a pop-up.
When “Show new message content” is turned on, the content of newly received messages can be viewed in a pop-up window.
Select “Notification sound” to change the notification sound alerts for new messages.
OS 6.0 (Marshmallow) version OS 7.0 (Nougat) version