• [1] 2002-12-03 (火) 13:15 名無しさん: Mail-Followup-To and Mail-Reply-To http://cr.yp.to/proto/replyto.html
• [2] The "Mail-Followup-To" header http://www.ietf.org/proceedings/98dec/I-D/draft-ietf-drums-mail-followup-to-00.txt
• [3] 返信先(Response targets): Reply-To, Mail-Reply-To, Mail-Followup-To http://im.qmail.jp/immhf/response.html

[4] [mew-dist 22724] Re: Mail-Followup-To: (2009-06-18 10:00:43 +09:00 版) http://www.mew.org/pipermail/mew-dist/2002-December/022419.html