Unsolicited Spam- how to stop it...?

My question is- if Yahoo provides the e-mail addresses that these individuals are using to forward unsolicited stock info to my e-mail, and the senders do not do not provide either an "unsubscribe" option OR EVEN AN OPTION TO REPLY WITH MY ANGST- (when I try to reply it gives me a failure notice)- shouldn't there be some place where I can tell Yahoo that it's "customers" are abusing their e-mailing priviliges by harring me? I understand that people are trying to sell something,and I really don't mind an occasional ad, but these people are burning me up daily wih no way to opt out.