Can DNS›Based Blacklists Keep Up with Bots?
Anirudh Ramachandran, David Dagon, Nick Feamster · Conference on Email and Anti-Spam · 2006
Many Internet Service Providers (ISPs), anti-virus companies, and enterprise email vendors use Domain Name System-based Blackhole Lists (DNSBLs) to keep track of IP addresses that originate spam, so that future emails sent from these IP addresses can be rejected out-of-hand. DNSBL operators populate blocking lists based on complaints from recipients of spam, who report the IP address of the relay from which the unwanted email was sent. To be effective in blocking spam, information in the blacklist must have the following properties: 1. Completeness. The blacklist must contain a reasonable