[ih] Email behavior (better subject ID...)

[Dave Crocker]

Replying to multiple messages on the thread, to reduce my posting count, 
and since they are all related...


On 9/4/2021 11:51 AM, Jack Haverty via Internet-history wrote:
> So that's what Reply-List does and why it sometimes appears as an option 
> for a message!
> 
> I admit being a victim of the Confusion.   I often get multiple copies 
> of mailing-list messages.  Some messages offer the "Reply-List" choice; 
> others just show "Reply".
> 
>   After a bit of experimentation, it seems that what happens depends on 
> how the original message arrived.  It appears that when mailing-list 
> messages somehow get my email address into a CC or TO field, behavior of 
> the reply options varies depending on whether I reply to the copy that 
> came through the mailing list or the one that came direct.

Your direct copy does not have the List-* header fields.  The message 
didn't go through the list system.  So you have only the usual 
reply/reply-all choices.

Via the list, the header fields are present and your user agent can make 
some choices, such as Reply-List, of course.

User agents vary on whether Reply defaults to reply-all or reply-author. 
 From very early and very hard experience I learned -- as I suspect all 
of you have -- that unintentionally replying to all recipients, such as 
is certain to happen when that's the default, ensures results varying 
from embarrassing to professionally disruptive.



> E.g., "Reply" to a message that came direct goes to the mailing-list; 

That's not a Thunderbird default, as I recall.  It certainly shouldn't 
be, per above.


> I've never seen anything like "List-Unsubscribe" offered in a menu. 

Yeah, one could wish for more integrated awareness of list issues in MUAs.

Such vagaries are, of course, the benefit and bain of having freedom to 
design mail user agents... freely.


  9/4/2021 11:59 AM, Ole Jacobsen via Internet-history wrote:
 > Notice how this is displayed in Apple Mail:

If there was supposed to be something like a graphic here, I didn't see it.


 > This is really crazy because not only has it changed the sender name 
to "Jack Haverty via Internet-history"
 > it has ALSO changed the recipient name to "touch--via..." and look 
what happens when I started this
 > reply:

Missing image, again?

Anyhow, it appears you haven't been seeing the From: field display-name 
modifications that have been going on since DMARC started getting 
expanded use, some years ago.

For author domains that publish a DMARC record -- and sometimes for all 
authors -- some/many mailing lists now patch the From: field to avoid 
rejection by final recipients.  Mailing lists break DMARC validation.

The hack is to change the From: field address, so it doesn't have the 
author's domain name, and to modify the display-name so it signals that 
a modification took place.  They also create a Reply-to field (if there 
wasn't already one -- and sometimes even if there is -- adding the 
original author's address, so that recipients can still reply to the author.

 > Dave Crocker??
 >
 > I know that this is a "feature" of my mail agent, but it also seems 
to be related to
 > how ISOC set up its mailing lists.

I think they were relatively late to the game in using this hack.  But, 
yeah.



On 9/4/2021 12:19 PM, Bernie Cosell via Internet-history wrote:
 > that's necessary.  the problem is that some isps have "registered"
 > every smtp server that is allowed to originate email  from their
 > domain.   when you send through a mailing list the originating
 > server isn't your server but the mailing list manager's server.
 > many, but not all, servers upon receiving it will bounce it as
 > not coming from one of the author's domain's allowed server.
 > what mailman does {and Likely other mailing list managers}
 > is replace all of the apparent origination info with "from
 > the mailing list"  generally {dunno on this list} mailman will
 > put the author's original email address in as a "cc:"

It's a bit different than that.

The actual culprit is DMARC, which enforces authenticated From header 
field domain name use.  If there is a DMARC record for that domain and 
the domain isn't authenticated, receiving systems might choose to reject 
the mail or handle it differentially.

Authenticated?  This is done by SPF or DKIM.  SPF is the mechanism that 
'authorizes' sending MTAs.  It validates for only one email hop.  DKIM 
uses a digital signature mechanism on some of the message object.  It 
works through regular email relaying, but pretty much never through 
mailing lists, which change some of the data that are part of the DKIM 
signature.

There's a recent, added mechanism, called ARC, that is intended to 
mitigate this mailing list DMARC problem.  We'll see how it fares.



On 9/4/2021 12:57 PM, Kenneth Porter via Internet-history wrote:
 > Perhaps we could upvote this bug:
 >
 > https://bugzilla.mozilla.org/show_bug.cgi?id=1512453

Please don't.  This is a truly terrible suggestion.  Understandable. 
But terrible.

A mailing list is a user-level process.  The mail is delivered and then 
re-posted.  User agents need to do whatever they feel reasonable.  There 
is 45 years of established practice for much of this.

DMARC has distorted things enough.



d/
-- 
Dave Crocker
Brandenburg InternetWorking
bbiw.net