From addresses and upas

From addresses and upas

[forsyth]

there might be a compromise.

we went through this here some time ago with an implementation of
the smtp part of upas as mangled by System V.4 and
somewhat unmangled by me.  it seems to be sufficient
to have the smtpd pick the right name to put in the Unix
`From ' header.  since it has already cracked the header and knows RFC822,
it's a fairly simple change.  it takes the `From ' address from the first of
Reply-to:, From:, Sender: and SMTP FROM:.  errors go to the SMTP FROM:.
(there should never be a Sender: without a From: but we get junk mail
from some machines.)

the Reply command in the mail reader just uses the `From ' address,
and needn't mess with the Wilt . (the Stilt) crud unless it wants to.

i didn't understand the recent discussion
until i realised that my From lines were being built as described by
our Unix machine before being sent to me on Plan 9,
and that's why my replies were going to the right address.
it also makes the seemail face list more interesting.