reputation block list(RBL)
A list of domain names, Uniform Resource Locators (URLs), or Internet Protocol (IP) addresses that are known security threats. Security systems throughout the Internet use RBLs to keep malicious or unwanted material from reaching victims. In addition to filtering out billions of incoming spam messages a day, RBLs block outgoing requests to malicious or disreputable IP addresses.
RBLs are created and maintained by commercial service providers, researchers, and public interest communities.