RFC 9057 · EXPERIMENTAL · 2021

Email Author Header Field

Overview

RFC 9057, “Email Author Header Field”, is an Experimental document published in June 2021 by D. Crocker. The canonical text is published by the RFC Editor.

Abstract

Internet mail defines the From: header field to indicate the author of the message's content and the Sender: field to indicate who initially handled the message on the author's behalf. The Sender: field is optional if it has the same information as the From: field. This was not a problem until development of stringent protections on use of the From: field. It has prompted Mediators, such as mailing lists, to modify the From: field to circumvent mail rejection caused by those protections. In effect, the From: field has become dominated by its role as a handling identifier.

The current specification augments the altered use of the From: field by specifying the Author: field, which ensures identification of the original author of the message and is not subject to modification by Mediators. This document is published as an Experimental RFC to assess community interest, functional efficacy, and technical adequacy.

Abstract as published in the RFC, via rfc-editor.org.

What “Experimental” means

Describes a specification that is part of a research or development effort, published so the community can gain experience with it.

Read this RFC

The canonical text of RFC 9057 is hosted at rfc-editor.org. Available in HTML,TXT,PDF,XML.

Other RFCs from 2021

Who Is Online

In total there are 264 users online: 0 registered, 254 guests and 10 bots.

Most users ever online was 5,555 on 17 Jul 2026, 3:23 am.

Bots: AhrefsBot Applebot Baiduspider Bingbot Googlebot Other Bot Other Crawler Other Spider PetalBot SemrushBot

Users active in the past 15 minutes. Total registered members: 372