I use abuse@[…] emails to report spam emails, at least some random ones. I won with a spammer at least one with help of abuse@yahoo and email@example.com.
Lately while checking who-is information on some IP i found that there is „abuse-mailbox” property. I thought there should be an application that would process spam email headers, and I found one:
Go get your spam headers and post them here, they’ll get processed… IP found… And finally a report for network providers will be send to abuse@ addresses.
PS. I wish I had a button in Gmail that would prepare a report automagically…