E-mailing Yahoo and asking them to prevent spam mail on yahoo groups?

I want to communicate with Yahoo and tell them they need to do a better job in filtering out spam mail that keeps coming to groups I'm a member of. I'm not sure where or how to do that. All they seem to offer are FAQ pages and e-mail forms. Does anyone know EXACTLY where to go on Yahoo to get on their case about putting a stop to spam mail on Yahoo, and make my voice heard?