From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Thu, 21 Oct 1993 23:05:29 -0400
From: Scott Schwartz schwartz@groucho.cse.psu.edu
Subject: No subject
Topicbox-Message-UUID: fdca3b7c-eac7-11e9-9e20-41e7f4b1d025
Message-ID: <19931022030529.RoxxpwGCeMMWvdkb9qpTa5lRk1wgKgzWQ3iFStEqC5E@z>


| The example that the RFC cites is a special mailbox where errors are
| to be sent could be used as the envelope address (e.g. the mailing
| list administrator's address).

That's exactly what we do.

| I think that your sysadmins are right: the UA should reply to the From: 
| address stored within the message.  I think that RFC821 specifies other 
| headers that can be used, too, such as Reply-To:.

RFC 822 says that.  See sections 4.3.1 and 4.4.4.