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