Outside of the bogus IRS calls, rarely are you going to get messages from most pests. They often lack a plan for an automatic response, what they're shopping for requires a live voice besides finding out if your number is working. If it's mandatory to have an answering device on, make sure you only use the default outgoing message instead of a recorded one containing your name. That's a way pests get your name to go along with your number so others know who you are ahead of time.
I would like to block this number but I refuse to pay extra for the service. Ooma offers it but they are also playing the game with the call-bot spammers. This is yet another call-bot that does not answer when I answer and calls me multiple times. I'm getting ready to dump my home phone number and just go to cell service. That would be a real shame because I've had this number for 16 years.