we block with manitu = nixspam as our primary RBL (followed by Spamhaus). Results are excellent. Their blocking is very reasonable. It's also possible to ask for inclusion in the whitelist. Obviously your great ISP Roadrunner isn't interested in inclusion or is sending out so many spam that they won't include it. Ask Roadrunner. Actually, Roadrunner has been known for years for big spam amounts originating from their network. I set it independently on our ACL for all mail servers years ago (not their whole IP range but all hosts matching their internet access assignment scheme). So, what you ask for is supporting one of the biggest spam output machinaries (besides Chinese ISPs) on the net. Thanks, no.
Because I'm not going to pay for colocation, or whatever.
Well, you are sending via monsterhost.com/bluehost.com which doesn't seem to belong to Roadrunner. So, what's your problem?
Kai