Jacob Palme <jpalme(_at_)dsv(_dot_)su(_dot_)se> writes:
At 16.39 -0700 04-09-17, Russ Allbery wrote:
"please try to suppress duplicates in mail sent to me and to the list."
Suppose a person subscribes to two mailing lists A and B, and has
his/her MUA sort their messages to two folders A and B. And suppose
there is a message sent via both lists. What is then the best
behaviour?
(a) Show each list-message as a separate message in the
folder for that list, and mark each of them as unread, so
that reading one copy will not set the other copy marked as
read.
(b) As (a) but some kind of link between the two messages.
(c) As (a), but reading the message in one folder marks it
as read also in the other folder.
I think most users would prefer (c), some might prefer (b).
For me personally, the ideal behavior would be (c) -- an emulation of
Usenet crossposting, in other words. However, that's something that I'd
want to be configurable on a per-list basis, since at times there may be
some reason why I want to see the messages from different lists separately
(the previously mentioned example of being in digest mode on one list, for
instance).
A related issue is if a message arrives in two copies, one with the
recipient as personal recipient, the other via a mailing list. When this
happens, the cause is almost always faulty handling by the sender's MUA,
and the intention is that the message should only be sent to/via the
list. So in this case, the best receiving MUA behaviour is probably to
completely suppress the personal copy of the message.
This is the way that I feel about it too, but as other people have
commented in this discussion, not everyone feels that way and some people
really want to get those personal copies.
All described above is easy to implement if the mailer keeps a data base
of message-ids and which messages they refer to.
It's not as easy as it sounds, since the message that should be
supppressed (in most of our opinions) is the personal copy, and that's the
copy that will almost certainly arrive first. You have to not show that
message to the user for some period of time while waiting for the list
copy to do this properly, which adds considerable complexity.
A problem is that a few messages do not have message-id, and a worse
problem is that some very unfriendly mailing list software will change
the message-id when expanding a message to a list.
If those were the worst problems we had to deal with, I would be very
happy, since then the problem would reduce to yelling at people who use
broken software. Always an enjoyable and necessary pasttime. :)
--
Russ Allbery (rra(_at_)stanford(_dot_)edu)
<http://www.eyrie.org/~eagle/>