In my wifes phone there is a phone number: "DELTA DO NOT ANSWER"

I do that because a) if I'm on SC and for some reason I'm missing calls my wife knows various ways to get a hold of me, b) I don't want anyone to answer the phone by mistake on those days I'm not on SC.

But like everyone else I listen to the messages, log in on the computer, contemplate calling back. But on the 1-800 calls are they going out in mass or one pilot at a time? I was under the impression in mass.