For a long time Yahoo! have offered a feedback loop which was developed and maintained by themselves. For a brief period this was available to the public but involved signing paperwork, sending it off and waiting over 6 weeks for it to be processed.

This was a major inconvenience to anyone who was mailing for several domains as the feedback loop itself was not done on an IP level like most, but instead a domain level using Domain Key technology which Yahoo! developed with Cisco.

Yahoo have now deprecated their feedback loop by preventing further signups and have now partnered with Return Path and are using them to deliver their feedback loop messages which uses ARF (Abuse Reporting Format)  back to the organisation who has signed up to receive the complaints. Organisations should then automatically process these and unsubscribe the complainant. If these ARF messages are processed correctly and complainants are unsubscribed this allows the organisations spam complaint levels to remain low and therefore a good reputation is maintained with Yahoo allowing better delivery of emails to Yahoo users.

For more information on the Yahoo! Feedback Loop see http://feedbackloop.yahoo.net/