[ On Thursday, November 13, 2003 at 10:52:26 (+0000), Phil Pennock wrote: ]
> Subject: Re: [Exim] Resent- headers
>
> I accept that the "-t" behaviour is unpleasantly ill-defined and
> problematic.
Well it's not, really, but.... :-)
> Pine may be misusing the headers
It almost certainly is misusing "resent-" headers. :-)
> but if Exim ignores all the X-Resent
> and stops treating any 'Resent-' header as special if it's separated
> from a "higher" (later prepended) 'Resent-' header by any other header
> (such as the block of Received: headers which you'd expect to see
> between multiple resends, unless some MTA isn't adding trace
> information)
Remember there is no such thing as ``multiple resends.'' It's not
logically possible for there to be more than one ``set'' of "resent-"
prefixed headers, despite RFC 2822's self-contradictory attempt to
describe them in brief, and despite the possibility that there may at
some time be multiple "resent-" prefixed headers with the same name in
one message. There is only the optional ``set'' of "resent-" prefixed
headers and the required ``set'' of headers without the prefix -- i.e. a
maximum of two ``sets'' of headers in any one message.
> -----------------------------< cut here >-------------------------------
> Received: from store-21.mail.nl.demon.net by mailstore for fred@???
> id 1AKEyT-000LIi-64-000LIk; Thu, 13 Nov 2003 10:45:17 +0000
> Received: from incoming-21.mail.nl.demon.net ([194.159.73.161]:4345)
> by store-21.mail.nl.demon.net with esmtp (Exim 4.24)
> id 1AKEyT-000LIi-64
> for fred@???; Thu, 13 Nov 2003 10:45:17 +0000
> Received: from samhain.noc.nl.demon.net ([194.159.72.214]:4286)
> by incoming-21.mail.nl.demon.net with esmtp (Exim 4.24)
> id 1AKEyT-0006q0-2S
> for fred@???; Thu, 13 Nov 2003 10:45:17 +0000
> Resent-Message-Id: <20031113104516.resent.fred-test.new@???>
> Resent-From: pdp+sample-Exim-test@???
> Received: from non-existant ([10.0.0.1]) by samhain.noc.nl.demon.net with ESMTP id 1234
> From: <phil.pennock@???>
> To: <bitbucket@???>
> Subject: test mail
> Message-Id: <20031113104516.fred-test.orig@???>
> Date: Thu, 13 Nov 2003 10:45:16 CET
> Resent-From: faked@???
> Resent-Date: Thu, 13 Nov 2003 10:45:17 +0000
>
> test message
> -----------------------------< cut here >-------------------------------
>
> Exim added the final header, "Resent-Date", but is claiming that the
> earlier ("faked@") resend was on that date, which is patently false.
Yes, it's the wrong date, but it's as close to what can be determined to
be the "right" date and adding the header is arguably allowed in order
to ensure that what it passes on is a complete ``set'' of "resent-"
prefixed headers.
(and if the above message were received with "MAIL FROM:<some@???>"
then a "Resent-To: <some@???>" could/should also be added)
Ideally such fixups should only be done when the SMTP client is a
"local" MUA (or when LMTP or "sendmail -t" are used, of course). In
such cases one would consider the receiving exim to be effectively
running as a Message Submission Agent (see RFC 2476), not a MTA.
In the real world it's also useful to do at least some of those fixups
when acting as a Local Delivery Agent as well (in order to make up some
for broken originators).
--
Greg A. Woods
+1 416 218-0098 VE3TCP RoboHack <woods@???>
Planix, Inc. <woods@???> Secrets of the Weird <woods@???>
