Re: [Exim] Resent- headers

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Author: Tony Finch
Date:  
To: exim-users
Subject: Re: [Exim] Resent- headers
Philip Hazel <ph10@???> wrote:
>
>So what? There doesn't *have* to be such a separator. Consider:
>
>Resent-From: ...
>Resent-Date: ...
>Resent-Cc: ...
>Resent_To: ...
>Resent-From: ...
>Resent-Date: ...
>Resent-Cc: ...
>
>To which set does the Resent-To: belong?


If the message has actually been resent twice there should be a
Received: header between the sets of Resent- headers.

>One doesn't usually expect to see anything nestled between Received:
>headers. The whole area is so ill-defined that different software does
>all kinds of different things.


Although it's horrible from the point of view of history and practice,
I think RFC 2822 is reasonably clear about the intended behaviour.
See the syntax for "fields" on page 18, which states that Resent-
headers are to be interleaved with Received: headers. I think Pine
is working to an older more ambiguous spec.

> "Each new set of resent fields is prepended to the message;
> that is, the most recent set of resent fields appear earlier in the
> message."
>
>The second clause in that sentence doesn't seem to say the same thing as
>the first clause.


It does to me. Received headers are prepended and appear from newer to
older as you read down.

>That seems clearer about prepending, but note the "kept in blocks",
>which suggests to me that interleaving with Received: is bad.


A block here means a set of Resent- headers and the associated
Received: lines. e.g.

    Received: from draco.cus.cam.ac.uk ([131.111.8.18])
        by red.csi.cam.ac.uk with esmtp (Exim 4.20)
        id 135709-000000-00
        for fanf2@???; Tue, 11 Nov 2003 13:57:09 +0000
    Resent-Date: Tue, 11 Nov 2003 13:57:09 +0000
    Resent-From: Philip Hazel <ph10@???>
    Resent-To: Tony Finch <fanf2@???>
    Message-ID: <E135709-000000-00@???>
    Received: from [193.201.200.170] (helo=chiark.greenend.org.uk)
        by draco.cus.cam.ac.uk with esmtp (Exim 4.20)
        id 123456-000000-00
        for ph10@???; Tue, 11 Nov 2003 12:34:56 +0000
    Date: Tue, 11 Nov 2003 12:34:56 +0000
    From: Tony Finch <dot@???>
    To: Philip Hazel <ph10@???>
    Message-ID: <E123456-000000-00@???>
    Subject: example


    blah


The first block is the first four header fields, the second is the fifth
header field.

Tony.
--
f.a.n.finch <dot@???> http://dotat.at/
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