> Botnets continue to be the number one source of junk email and will likely continue as we add more and more insecure doorbells, garage openers, refrigerators, etc, to our home networks.
Surely that's an argument against blocking IPs?
Unless I suppose you argue they're predominantly in homes; and homes are predominantly not running (intentional, well-behaved) email servers, so sorry-not-sorry those who are.