Alan Stebbens posted the formail -r[t] rank bar graph from version 3.11pre4.
It might be easier to follow as a top-to-bottom listing (and again, Tom
Zeltwanger appears to be using one of the older versions where From_ was
mistakenly overpromoted). These are the rankings in version 3.11pre4:
formail -r: formail -rt:
Resent-Reply-To: Resent-Reply-To:
Resent-Sender: Resent-From:
Resent-From: Resent-Sender:
Return-Receipt-To: Reply-To:
Errors-To: From:
Reply-To: Sender:
Sender: Return-Receipt-To:
From_ Errors-To:
Return-Path: Return-Path:
Path: From_
From: Path: