It doesn't have hard numbers but it does discuss how to analyze mass spamming strategies. I found it very eye opening. https://www.microsoft.com/en-us/researc

It doesn't have hard numbers but it does discuss how to analyze mass spamming strategies. I found it very eye opening. https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/WhyFromNigeria.pdf https://www.microsoft.com/en-us/research/wp-content/uploads/... "False positives cause many promising detection technologies to be unworkable in practice. Attackers, we show, face this problem too. In deciding who to attack true positives are targets successfully attacked, while false positives are those that are attacked but yield nothing."