Feedback loop

A Feedback Loop (FBL) is an automated stream of spam reports sent by prior agreement between individual receiving and sending networks, often based on a "This Is Spam" button in the user interface. FBLs are intended to help streamline and automate the spam reporting process with specific machine-readable parts. A standard Abuse Reporting Format (ARF) is specified and implemented for FBLs. ARF follows existing RFC2045 MIME standards for e-mail (and the earlier RFC1341).

A single spam report could be a fluke or someone reporting mail they actually signed up for, or it could represent 10,000 or more spam recipients. For wide-scale, pure-spam mailshots, the reporting rate is often even less than one in 10,000 due to filtering and "LART fatigue" of many who used to report spam. In general, hand-crafted reports are more likely to be actual spam than reports from automated "This Is Spam" (TIS) buttons. Even TIS reports average in excess of 80% spam, though. Evaluate reports as you will; ignore them at the risk of your network's reputation.