Comment Re:What's the point? (Score 1) 97
Yes, a human can look at the standard whois database. A mail server cannot easily do that. If you would RTFA, you would see that it is a DNS RBL that your mail server can query.
Sure, you could write a script to do that, but if someone hits you with a spam run, you're going to get banned from the whois databases pretty damn fast.