@hrefna I understand the term quite well. When I dealt with it, "collateral damage" meant "block all email from entire ISPs and all their customers". And I was fine with that, because measures that didn't go that far had been tried repeatedly for years and weren't working. Email spam was still a massive problem even with individual anti-spam measures in place. So, massive collateral damage it was. And you know what? It worked. ISPs started to clean up their acts.