Many people realize that stopping e-mail spam at the source, while effective, is not easy. This TechWeb article on the state of Massachusetts' efforts to stop just one spam ring is illustrative of the problems.
For example, they are trying to catch a Russian, living in Boston, using domains registered in Monaco, Australia and France, and servers in China, Korea, Brazil and Taiwan.
All I can say is good luck.
In the mean time, use spam filters such as, but not limited to, SpamAssassin, PopFile, or Clam Anti-Virus and you should be able to catch 98 percent of the spam before it makes it to your in box.
