Thanks Joe, well lady at Verizon, says to block anyway.. who knows.

I contacted two 3rd party companies like that and they both don't have ability, to allow the spammer to at least leave a voice mail, so its a deal breaker. I can't trust false positives, so going pass until these servies allow that. Verizon does allow that with their app, but my plan is not eligible to use their app. So stuck.