@profoundlynerdy But that's just wrong, nearly all common and business e-mail hosts directly discard part of the incoming spam or don't even allow mail from the most spammy networks. Whole ranges are completely blacklisted by most existing e-mail hosts, and some ISPs block outgoing SMTP ports because of botnets.

We too have some completely blacklisted instances that we don't want to interact with at all and some just silenced that people can still follow if they want.