This is my personal list of usefull services to find and report spam.

Cyberabuse whois

Geek-Tools whois

This is a standard spam report:

I’m receiving spam mails from one of you’re IP-adresses.

Full headers below

Another standard spam report:

Hello. The spammer below is either using your resources to send out bulk
unsolicited commercial e-mail (“spam”) or is deceptively trying to make it
look like he is. In either case, a legitimate company like yours probably
would not approve. The information below should be all you need.

–begin full headers–