bug#25891: 25.2; Reply inRMAIL sometimes fails

[charles@aurox.ch (Charles A. Roelli)]

> Date: Tue, 19 Sep 2017 21:34:26 +0100
> From: jpff <jpff@codemist.co.uk>
> 
> [1:text/plain Hide]
> 
> 
> Attached is a mailfile (set rail-mode) with one message.  Typing "r" to
> reply I see
> ------------------------------------------------------------------
> From: jpff <jpff@codemist.co.uk>
> To: Steven Yi <stevenyi@gmail.com>
> CC: Victor.Lazzarini@mu.ie
> In-reply-to:
> 	<CANtcCs7-TwLw9PiOvQBYyertQbWurCsJ-i9B9JjGQTZxoaNesg@mail.gmail.com>
> 	(message from Steven Yi on Tue, 19 Sep 2017 08:39:00 -0400)
> Subject: Re: Next release
> BCC: jpff@codemist.co.uk
> References: <9c571770-2e28-4b78-95c6-baad81925043@codemist.co.uk> <63268264-9DE9-4EDE-AE92-BC3236D5A1FF@mu.ie> <CANtcCs7-TwLw9PiOvQBYyertQbWurCsJ-i9B9JjGQTZxoaNesg@mail.gmail.com>
> --text follows this line--
> 
> ==John ffitch
> ------------------------------------------------------------------------
> (that is my automatically inserted signature)
> 
> Adding text `"test" to this and sending the message I get (my BCC) is
> ------------------------------------------------------------------------
> Date: Tue, 19 Sep 2017 21:13:14 +0100
> From: jpff <jpff@codemist.co.uk>
> To: Steven Yi <stevenyi@gmail.com>
> Cc: "Victor.Lazzarini@mu.ie"
>     <CANtcCs7-TwLw9PiOvQBYyertQbWurCsJ-i9B9JjGQTZxoaNesg@mail.gmail.com>
> Subject: Re: Next release
> 
> test
> ==John ffitch
> ------------------------------------------------------------------------
> which is clearly ill formed -- and indeed I also get the message
> ------------------------------------------------------------------------
> Date: Tue, 19 Sep 2017 21:13:51 +0100
> From: Mail Delivery System <Mailer-Daemon@codemist.co.uk>
> To: jpff@codemist.co.uk
> Subject: Mail delivery failed: returning message to sender
> Parts/Attachments:
>    1   Shown      8 lines  Text
>    2   Shown    161 bytes  Message, "Delivery Status"
>    3   Shown    1.2 KB     Message, "Re: Next release"
>    3.1 Shown      3 lines  Text
> ----------------------------------------
> 
> This message was created automatically by mail delivery software.
> 
> A message that you sent could not be delivered to one or more of its
> recipients. This is a permanent error. The following address(es) failed:
> 
>   CANtcCs7-TwLw9PiOvQBYyertQbWurCsJ-i9B9JjGQTZxoaNesg@mail.gmail.com
>     Unknown user
> 
> 
>     [ Part 2: "Delivery Status" ]
> 
> Reporting-MTA: dns; codemist.co.uk
> 
> Action: failed
> Final-Recipient:
> rfc822;CANtcCs7-TwLw9PiOvQBYyertQbWurCsJ-i9B9JjGQTZxoaNesg@mail.gmail.com
> Status: 5.0.0
> 
> 
> 
>     [ Part 3: "Included Message" ]
> 
> Date: Tue, 19 Sep 2017 21:13:14 +0100
> From: jpff <jpff@codemist.co.uk>
> To: Steven Yi <stevenyi@gmail.com>
> Cc: "Victor.Lazzarini@mu.ie"
>     <CANtcCs7-TwLw9PiOvQBYyertQbWurCsJ-i9B9JjGQTZxoaNesg@mail.gmail.com>
> Subject: Re: Next release
> 
> test
> ==John ffitch
> ------------------------------------------------------------------------
> Experiments suggest that if I move the I-reply-to lines to the end of
> the headers it works
> 
> Hope that is clear?

Yes, thank you.  So it looks like the "In-reply-to:" line is being
removed at some point while sending the message.  Can you also
reproduce this from emacs -q?  I tried to, without success.

Additionally, after you send the message with the broken
CC/"In-reply-to:" headers, can you switch to the buffer "*sent mail to
<recipient>* (where <recipient> is the recipient of the message) and
show the contents?

Thanks in advance.