I use throwaway email addresses of the form [email protected]
whenever I sign up to newsletters. When I get spam to them I unsubscribe from the newsletter and forward them to ":blackhole:". Is there somewhere I could forward them to instead that could use them for classifying spam? I'm thinking some kind of honeypot? Or would it just be a waste of bandwidth?
[email protected] is meant for US citizens to send e-mail to that is "deceptive". If you are manually sorting through your spam e-mail you can help out by forwarding the e-mail there to maybe put a legal dent in spammers.
SpamCop, which is a spam filtering service you described also has a procedure for this. It would be better to read their blurb instead of me reposting it:
http://www.spamcop.net/fom-serve/cache/402.html