Tracking Spammers: Tools 

[NT] nslookup: Translates an IP address into a domain name.

[NT] tracert: Displays the path from your computer to the remote one (i.e., the suspected spammers)

[UNIX] whois: Provides a domain address and contact information.

[Internet] www.dejanews.com: Search engine for UseNet posts, useful for learning a spammer's identity, history, and verifying suspicious From: addresses and routing domains.

See also:

Getting Started
Time Savers