https://app.knowbase.one/vault/rfc/docid/7014
RFC6449: Complaint Feedback Loop Operational Recommendations
Internet Engineering Task Force (IETF) J. Falk, Ed. Request for Comments: 6449 Messaging Anti-Abuse WG Category: Informational November 2011 ISSN: 2070-1721 Complaint Feedback Loop Operational Recommendat...