On Fri, Oct 09, 2020 at 09:24:34PM +0200, c.buhtz@posteo.jp wrote:
> Hi,
> 
> I had this discussion in several mailinglists but gave up.
> 
> But I am suprised to see this phenomenon in a emacs related (means:
> "super nerdy") mailinglist, too.
> 
> So tell me please how do you handle this "problem"? Or do I setup
> something wrong with my list account?

There is no clear-cut answer to that. For mailing lists which allow
posting by non-subscribers (this is one), reply-to-all makes more
sense to reply-to-all, since you can't be sure that everyone is
subscribed.

As for what I do, I have a mail filter (procmail) which weeds out
duplicates fairly effectively.

For this list, specifically, which is managed by Mailman, you can
tell the list manager [1] to not send you a duplicate when your
address is in the To: or Cc: header field. Note that you'll get
the copy sent to you, not the one sent via the list; if you are
filtering based on list headers, this might not be what you want.

To appreciate the whole "interesting" complexity see [2]. In a
nutshell, there's no ideal solution working for all tastes.

Cheers

[1] https://www.gnu.org/software/mailman/mailman-member/node21.html
[2] http://david.woodhou.se/reply-to-list.html

 - t