Re: [Exim] -t and Resent- header lines

Top Page
Delete this message
Reply to this message
Author: Exim Users Mailing List
Date:  
To: Philip Hazel
CC: exim-users
Subject: Re: [Exim] -t and Resent- header lines
[ On Thursday, May 8, 2003 at 14:00:06 (+0100), Philip Hazel wrote: ]
> Subject: [Exim] -t and Resent- header lines
>
> The -t documentation in the Exim documentation states:
>
>     If there are any "Resent-" headers in the message, an error is
>     generated, and Exim gives up. RFC 2822 talks about different sets
>     of "Resent-" headers (when a message is resent several times), and
>     it is not at all clear how -t should operate in this situation.
>     Experiments with Sendmail have shown that it amalgamates multiple
>     sets of "Resent-" headers when -t is used.  This does not seem to
>     be in the spirit of RFC 2822.

>
> I have now been informed by no less an authority than RMS that emacs
> expects an MTA to "handle" Resent- header lines.


Sorry Philip, but that all happened because of my doing! Quite a long
time ago I had submitted a change to emacs so that it's sendmail
interface would work properly with resent-* headers with sendmail, as
well as of course with smail, and postfix (and presumably zmailer too,
though I haven't tested the latter in quite some time).

Somewhat more recently exim was installed on one of the gnu.org machines
and one of its users finally tried to send a message with resent-*
headers and discovered that exim complains. Eventually the bug report
reached me just the other day and RMS asked me to explain.

I showed RMS the section of your exim manual documenting the behaviour
in exim, as well as showing the way the other mailers work and I told
him I'd write a proposal to you suggesting that exim's behaviour be
changed to match that of sendmail and the rest. It seems he's beat me
to it! ;-)

> Does anybody have any
> views on some kind of reasonable specification? Note that a message that
> starts off
>
> Resent-From: xxxx
> Resent-To: xxxx
> Resent-To: xxxx
> Resent-To: xxxx
> Resent-From: xxxx
>
> is ambiguous as to which "to"s belong to which "from". I don't want to
> have to add artificial intelligence to Exim to try to sort out this kind
> of problem.


The most important thing is to treat them all as just replacements for
the same headers that don't have the "resent-" prefix, since that's
exactly what they are. That rule includes dealing with missing headers,
such as message-id and so on. The only exception, IIRC, is received
headers.

FYI, Smail-3 sends to them all, just as it would if the "resent-" prefix
was not present.

$ smail -v -bv -t
new spool file is /var/spool/smail/input/19Dngh-000B3kC
resent-from: foo
resent-to: 1
resent-to: 2
resent-to: 3

hello

3 ... not deliverable: no such user or mailbox
2 ... not deliverable: no such user or mailbox
1 ... not deliverable: no such user or mailbox


$ smail -v -bv -t
new spool file is /var/spool/smail/input/19DnhK-000B3kC
to: 1
to: 2
to: 3
3 ... not deliverable: no such user or mailbox
2 ... not deliverable: no such user or mailbox
1 ... not deliverable: no such user or mailbox

--
                                Greg A. Woods


+1 416 218-0098;            <g.a.woods@???>;           <woods@???>
Planix, Inc. <woods@???>; VE3TCP; Secrets of the Weird <woods@???>