Re: Please, don't reply to spam -- much less on list

[Nicolas George <george@nsup.org>]

tomas@tuxteam.de (HE12025-06-28):
> MUA "bounce" is not exactly the same (the user has a chance to
> specify *which* address to send the bounce to, for one), but
> technically so close (as much of the headers as possible remains
> unchanged), that calling it a bounce does make sense.

This is not accurate.

MUA bounces are injected as is as an outgoing mail, with all their
headers and all their bodies. Any change comes later in the transmission
and delivery.

MTA bounces, i.e. delivery status notifications, are entirely new mails,
with minimal headers telling you where it comes from and with an
(usually incomprehensible) explanation in the body. They contain the
full header of the original mail and sometimes but not always its body,
either directly in the body or as a MIME attachment.

In termes of structure, MTA bounces are much closer to MUA forwards than
MUA bounces. And MTA forwards are much closer to MUA bounces than MUA
forwards.

Regards,

-- 
  Nicolas George