Email addresses are irrelevant, unless the spammers are stupid enough to give you a valid reply address (like "write to sales@idiot.com for a catalog!"). The name of the game in spam-busting is the Received: headers.

Track the spam back to the SMTP server it was sent from. Do a WHOIS on that domain. Email the listed sysadmin, as well as abuse@that_domain.com and explain how open relays are just like letting spammers steal their money. Also:

1. If they list a web site, WHOIS again and send more email. If they own the domain, TRACEROUTE and do recursive WHOISes until you find their provider.
2. If the URL is a weird 10 to 12 digit decimal number, convert it to 8 digits of hex, break the hex into 4 parts, and convert the parts back to decimal to get the real IP. Then DNSQuery on the IP.
3. If they have an 800 number, call them repeatedly and waste their time.

Source: Posted by "Frankie" on http://slashdot.org/. Post attached to Spammers Hit Wireless Phones | 04/12/2000

If you don't have the attention span to do that, go to spamcop, at http://spamcop.net Once you verify your e-mail address, you are given an URL you can go to and submit your spam to a script that parses the headers and message for IPs, URLs and E-Mails, then checks them in the abuse.net database for a complaint e-mail address, to which it dispatches an e-mail. I find it works well. I ran it alongside several of my own searches, and it turned up complaint e-mail addresses far quicker than I can.