On Tue, 30 Oct 2007, W B Hacker wrote:
> > would exim add a second header or
>
> Yes.
I suppose the question this raises is how does anything downstream looking
at Precedence: header content interpret two such headers?
I'm not really expecting an answer, but the original poster might want to
consider and maybe investigate what Exchange does with mail that has two
Precedence headers: one from the original mail with a value other than
"(bulk|junk|list)", plus one added by his Exim with one of those values.
Which does Exchange believe? And does the order they appear in the
headers matter?
(I note that RFC 2076 describes the use of Precedence header as
"Non-standard, controversial, discouraged", although clearly it has
extensive use via mailing list managers and the like. It also mentions
the example value of "first-class", which I have never noticed).
I hadn't actually considered using this header to help Exchange keep a lid
on autoresponses to messages found to be spam, so this in itself is
interesting. I think my approach would be to:
1. make the assumption that no end client really uses a value of
Precedence: that is other than bulk|junk|list, especially if the message
is likely to be spam
2. rename any existing Precedence: header to be X-Precedence: or
something, so at least its original value is preserved somewhere if the
user really wants to see it
3. then let Exim add "Precedence: bulk" to allow Exchange to detect it.
However, I see from:
http://msexchangeteam.com/archive/2006/10/06/429115.aspx
that Exchange 2007 will also not reply to a message with a header
"X-Auto-Response-Suppress: OOF", so this may be a solution more palatable
to the original poster. Shame - it would have been a good opportunity for
Exchange to promote the use of the (standard) Auto-Submitted header rather
than create yet another one. (Other potential for
"X-Auto-Response-Suppress" appear to be "DR" and "AutoReply",
comma-separated where several are needed, but documentation appears to be
sparse. DR == Delivery Report??).
Jethro.
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Jethro R Binks
Computing Officer, IT Services
University Of Strathclyde, Glasgow, UK
