nt size="2 Say the name Spamhaus in a room full of e-mail marketers and you  likely will get a lot of dirty looks. It runs one of the biggest and  most widely used blacklists available to Internet service providers  and corporate administrators for identifying and blocking spam.  The  folks who use the list find it extremely helpful in keeping spam out  of their networks. Spamhaus currently protects about 500 million mailboxes with its  various blacklists.  It also works closely with international law  enforcement, providing evidence and data to pursue criminal spammers  on the Internet. The Spamhaus project has become one of the most respected anti-spam  organizations in the world.  Yet some marketers feel that the  Spamhaus Block List is too easy to get on and often difficult to get  off. Marketers need to understand what is happening across the vast  communication network to which they belong.