https://app.knowbase.one/vault/rfc/docid/2113
RFC1894: An Extensible Message Format for Delivery Status Notifications
Network Working Group K. Moore Request for Comments: 1894 University of Tennessee Category: Standards Track G. Vaudreuil Octel Network Services ...
https://app.knowbase.one/vault/rfc/docid/7101
RFC6522: The Multipart/Report Media Type for the Reporting of Mail System Administrative Messages
Internet Engineering Task Force (IETF) M. Kucherawy, Ed. Request for Comments: 6522 Cloudmark STD: 73 January 2012 Obsoletes: 3462 Category: Standards Track ISSN: 2070-1721 ...