You can be informed of new messages in addition to the notification LED by the LED camera flash of the Samsung Galaxy S7 Edge.
Here the camera LED flashes periodically until you have read the notification. To use this feature on your Samsung Galaxy S7 Edge, you must activate this in the settings. Just open the following submenu on the Samsung Galaxy S7 Edge:
Home Screen --> App Menu --> Settings --> Accessibility --> Hearing
Here you can find and select the "Flash Alert". Use the control bar to activate the option for your Samsung Galaxy S7 Edge.
You will be from now on informed about new notifications with a regular flash of your camera flash.