Hello & Welcome to Just Answer,
I'm Greg and will do my best to assist you today.
Sorry to hear of any issue you are having with your phones.
To help you with this issue, may I ask:
1) How many TOTAL cordless handsets do you have with this system, and if more than one, do ALL handsets display this "New Voice Mail" message?
2) What phone service provider (phone company) you have for this phone line?
3) Can you press the TALK button and listen QUICKLY (for the dial tone), and tell me if you hear ANYTHING BEFORE the clear dial tone?