Blacklists or blocklists are lists of IP addresses, domain names, email addresses or content of the headers or the body, or some combination of these different types, that can be used to help identify spam. A special subset of IP address and domain name lists exist which can be queried using DNS, which are called DNS Blackhole Lists or DNSBLs. Blacklists can be unverified and cause “collateral damage”; their criteria for listing may not be clear.
Those blacklists listed here are just a tiny subset of all of the private access lists and ACLs that exist to block spam from private networks; that larger set is the source of the death of a thousand cuts that any spam friendly provider should eventually experience. They may not have the clout of SPEWS, but they may last even longer.