NEC Univerge Dtl-12d-1 680002 Dt300 Refurb Warranty "red light blink phone" Questions

and the red light is blinking. How do I remove this? Once the messeges are cleared, the light will stop blinking. There should be a button to push, which will allow you to access the messeges options

My phone is not ringing? I can see the red light blinking though. Please check the volume settings or switch, it may be set on mute.