Re: Postfix based mailing list and yahoo's errors

[Greg Troxel <gdt%lexort.com@localhost>]

Mayuresh <mayuresh%acm.org@localhost> writes:

> On Tue, Jul 09, 2019 at 08:35:10PM -0400, Greg Troxel wrote:
>> https://www.unicom.com/pw/reply-to-harmful.html
>> http://marc.merlins.org/netrants/reply-to-still-harmful.html
>
> Thanks. I understand and appreciate the write ups. Firstly, I'll try not
> adding Reply-To and see if that accommodates yahoo. If not, I'll have to
> change the From to list address and Reply-To to sender's as yahoo
> suggested.

It's up to you to decide if you want to accomodate yahoo at all.   I
would be disinclined to do so.

I remembered another point, which is that the NetBSD lists (which
probably have very few yahoo subscribers :-)

  do not modify the subject
  do not modify the body

This is actually the very traditional appraoch, and I believe it is
still the best approach.  I think that this scheme is not objected to by
yahoo, because outgoing mail from yahoo arrives back at yahoo intact, so
that body and header signatures check, just with more Received lines and
possible List-Foo lines.  I suggest trying that.

If you do decided to accomodate yahoo, it should be possible to
only modify messages with yahoo senders.  I don't think it is reasonable
to munge other people's messages because of yahoo.   I have the
impression mailman can do this.

Another approach is to have a separate email address at the list domain
for each yahoo member, and use that as the From:, and forward what's
received back to the yahoo address.  That presserves the normal scheme
that From: is author and no Reply-To added by anyone other than the
author.  I have not seen this done, and perhaps there is some problem I
am not envisioning.

> Without arguing it to be correct, an expectation that "Reply should go to
> list automatically" exists. Most users won't bother to understand above
> points.

Yes, there is much thinking out there based on a lack of understanding:

  Some people don't understand the conceptual difference between the MUA's
  "Reply" and "Reply All" actions.

  Using "reply" is expected to send an email to the author (and only the
  author, and definitely not the list).  Some people don't understand
  that this point is overwhelmingly important, and that violating it
  causes serious problems and is therefore completely unacceptable.  (In
  particular, I think it's far more acceptable to ask yahoo subscribers
  to get a different mail provider than to violate this rule.)

There are other headers, such as Mail-Followup-To, which AIUI are
intended to all "reply all" to be directed slightly differently.  That's
fine, as reply all is meant to include the list.