Xref: utzoo comp.mail.sendmail:1221 comp.mail.uucp:3837 comp.mail.misc:2737 comp.mail.headers:538
Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uunet!atina!mrecvax!mauricio
From: mauricio@mrecvax.UUCP (Mauricio Fernandez)
Newsgroups: comp.mail.sendmail,comp.mail.uucp,comp.mail.misc,comp.mail.headers
Subject: I need information about mail aknoledgements.
Keywords: Unix Mail, Return-Receipt-To, acknowledge
Message-ID: <470@mrecvax.UUCP>
Date: 7 Dec 89 18:25:00 GMT
Reply-To: mauricio@mrecvax.UUCP (Mauricio Fernandez)
Organization: M.R.E. y C. Bs. As. Argentina
Lines: 10

I'm designing an e-mail system to be implemented over sendmail.
The user should be able to ask the system, at message sending time,
to indicate him whether the recipient has already read the message.
Of course, this won't happen if the recipient is outside of this system
unless there exist any standard around dealing with this.
I do need any information about implementations of this kind of service,
strategies that cope with this requirements, headers etc.
Please answer me, via e-mail. I'll summarize.
-- 
Mauricio Fernandez                 mauricio@mrecvax.mrec.ar