The blinking LED light is used to notify you when a new email was received. You can customize the LED notifications by following these steps: More (o o o) | Notifications | Scroll to the account | Sound|Vibrate|LED | Enable LED Light (Enable/Disable LED notifications) | Notification LED Color (Customize the LED notification color). Enjoy the rainbow!

Please note: Some devices support only basic colors and other devices do not have an LED light entirely.