Spamhaus is an international organisation whose mission is to track the Internet's spam operations and sources, to provide dependable realtime anti-spam protection for Internet networks, to work with Law Enforcement Agencies to identify and pursue spam and malware gangs worldwide and to lobby governments for effective anti-spam legislation.

Founded in 1998, Spamhaus is based in Geneva, Switzerland and London, UK and is run by a dedicated staff of 38 investigators, forensics specialists and network engineers located in 10 countries.

Spamhaus maintains a number of security intelligence databases and realtime spam-blocking databases ('DNSBLs') responsible for keeping back the vast majority of spam and malware sent out on the Internet. These include the Spamhaus Block List (SBL), the Exploits Block List (XBL), the Policy Block List (PBL), the Domain Block List (DBL) and the Botnet Controller List (BCL). Spamhaus DNSBLs are today used by the majority of the Internet's Email Service Providers, Corporations, Universities, Governments and Military networks.

To meet public demand for its DNSBLs, Spamhaus has built one of the largest DNS infrastructures in the world. Its network of over 80 public DNSBL servers spread across 18 countries serves many billions of DNSBL queries to the public every day, free of charge.