Experimental Physics and
Industrial Control System

"J. Lewis Muir via Tech-talk" <[email protected]> · Thu, 29 Nov 2018 15:25:44 -0600

On Thu, Nov 29, 2018 at 11:21 AM Mark Rivers <[email protected]> wrote:
> Here are the complete headers of that message as retrieved from Outlook:

[snip]

> Note that I was mistaken, there is a To: field, it is just higher up in the header and I missed it.
> Note also that in this message To: and From: are not the same, unlike what Ralph said.
>
> To: "[email protected]" <[email protected]>
> From: =?gb2312?B?y+/M7NCl?= via Tech-talk <[email protected]>
> Reply-To: =?gb2312?B?y+/M7NCl?= <[email protected]>
> Sender: <[email protected]>

Your copy of the email and mine are essentially identical after I
remove Received headers and such:

===

--- muir-header-filtered.txt 2018-11-29 11:58:51.000000000 -0600
+++ rivers-header-filtered.txt 2018-11-29 12:03:59.000000000 -0600
@@ -25,6 +25,10 @@
  <mailto:[email protected]?subject=subscribe>
 From: =?gb2312?B?y+/M7NCl?= via Tech-talk <[email protected]>
 Reply-To: =?gb2312?B?y+/M7NCl?= <[email protected]>
-Sender: [email protected]
+Sender: <[email protected]>
 Errors-To: [email protected]
-Return-Path: <[email protected]>
+Return-Path: [email protected]
+X-MS-Exchange-Organization-Network-Message-Id:
fef35cc2-4dfc-4e60-74fe-08d655de68f9
+X-MS-Exchange-Organization-AuthSource: carsmail.CARS.APS.ANL.GOV
+X-MS-Exchange-Organization-AuthAs: Anonymous
+X-MS-Exchange-Transport-EndToEndLatency: 00:00:00.2031686
===

So, in mine, I don't have the angle brackets around the Sender and
Return-Path addresses; that doesn't matter.  And I don't have the
X-MS-Exchange-* fields; that doesn't matter either.

This tells me the difference is in the MUA.  Using Gmail, if I click
the "Reply to all" button for that email, it creates a reply with the
following header fields:

  To: [email protected]
  Cc: [email protected]

For you with Outlook, it doesn't do that.

And I just tried with iOS 12.1 Mail, and it doesn't do that either: I
tap the Reply button and the only reply choice is "Reply"; there is no
"Reply All", so it's a pain to reply-all from iOS Mail.

As you alluded to, I think this change in behavior may be due to
Argonne's email changes, DMARC in particular.  Andrew, or whoever the
list administrator is, would probably know.  Specifically, it seems
that Mailman, the mailing list manager software for the Tech-Talk
list, is rewriting the header as follows.

The field

  From: [name] [email-address]

becomes two fields

  From: [name] via Tech-Talk <[email protected]>
  Reply-To: [name] [email-address]

I think this rewrite is causing the reply-all function of some MUAs
(e.g., Outlook and iOS Mail) to not work correctly.

It would be helpful to know exactly how Outlook and iOS Mail determine
the recipients for a reply-all.  Maybe someone has documented it
somewhere; I don't know.

Maybe Outlook and iOS Mail honor a Mail-Followup-To or Mail-Reply-To
field, and the problem could be solved by making the mailing list
manager software add one or both of those fields to the header of any
Tech-Talk email it sends; I have no idea.

Or maybe there's a mailing list manager software option that could be
tweaked.  Based on the X-Mailman-Version header field, the Tech-Talk
list is being managed by Mailman 2.1.12.  That is the stable 2.x
series version, but there is a stable 3.x series version too: Mailman
3.2.0.  In 3.2.0, I see an interesting option "reply_goes_to_list" at

  https://mailman.readthedocs.io/en/latest/src/mailman/handlers/docs/dmarc-mitigations.html

that says

  reply_goes_to_list

    If this is set to other than no-munging of Reply-To:, the original
    From: goes in Cc: rather than Reply-To:. This is intended to make
    MUA functions of reply and reply-all have the same effect with
    messages to which mitigations have been applied as they do with
    other messages.

I wonder if using this option would make the rewrite of

  From: [name] [email-address]

become

  From: [name] via Tech-Talk <[email protected]>
  Cc: [name] [email-address]

and if that would make the reply-all function of Outlook and iOS Mail
work again.

Yet another approach is to, if you're willing and able to insert a
header rewriting program into your local mail delivery pipeline,
rewrite the header back to how it was before the DMARC changes.  That
is, for any Tech-Talk mailing list message, rewrite

  From: [name] via Tech-Talk <[email protected]>
  Reply-To: [name] [email-address], [original-reply-to]

back to

  From: [name] [email-address]
  Reply-To: [original-reply-to]

But if there was a Reply-To field in the original, then I don't know
exactly how the first rewrite works; hopefully it adds to the Reply-To
field address list and doesn't just overwrite it.  If it overwrites
it, then there's no way to recover the original.  If it prepends or
appends, then you can just undo whatever it does to rewrite back to
the original.

Lewis


Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System