Empirical research of IP blacklists

IP blacklisting of spamming IP addresses is one of the oldest techniques to fight spam. However, while one of the oldest it is one of the most effective, too. Two analysis methods are described and results thereof are presented in this work. It is revealed that a lot of spam originates from short-lived IP addresses which are often not blocked by IP blacklists. This raises the need of highly dynamic blacklists. List properties of well-known blacklists are begin given as part of this paper. Furthermore, a glance of mail receiver distribution by country is included.