Return-Path: <spammer@example.com>
From: SPAM ® <spammer@example.com>
To: <a@b.c>
Subject: spam ® spam
Message-Id: <20120302063755.0FE2122017@a.a.a.a>
Date: Fri,  2 Mar 2012 07:37:55 +0100 (CET)

https://github.com/sup-heliotrope/sup/issues/205