reply-all should be discouraged

[cognitive.libertarian+ml at gmail.com]

* Derek Atkins <warlord at MIT.EDU> [2010-02-20 18:23]:
> >> > Please remember to CC this list on all your replies.
> >> > You can do this by using Reply-To-List or Reply-All.
> >
> > Please don't encourage use of "reply all".  Everyone who posts is
> > inherently on the list, and gets the message.  We don't need a
> > duplicate.  
> 
> Nope, everyone who posts is *NOT* inherently on the list, so they do
> NOT inherently get the message.  There's this concept called
> "moderation" where you can go through and manually allow messages
> through to the list for those who were not subscribed..  We
> encourage anyone and everyone to ask questions here, even if they
> are not subscribed.

That's fair enough, but it doesn't justify sending dupes to
subscribers on a regular basis, without their request.  If someone
needs a personal copy of responses because they don't have access to
the list replies, they can request it specifically because it's an
exceptional case.  That's the regular practice on mailing lists to
reduce the problems imposed on subscribers.

The proper way for someone to request personal copies simply to
include the header "Mail-Followup-To: gnucash-user at gnucash.org, [their
personal address]".

> > Reply-all is often used by those who have substandard mail clients
> > that don't offer Reply-To-List, and it creates problems for those who
> > have proper mail filtering (eg. procmail keying on List-Id).  Dupe
> > filtering fails on the user end because nothing ensures that the list
> > reply is the first in sequence, so half the time the list version gets
> > canned.
> 
> This is why you should do dup checking based on Message-Id, which
> catches these dups just fine.

It doesn't work, because the first message processed is often (but not
always) the personal copy.  So the message containing the list headers
usually gets trashed.  

Dupe checking is also problematic because not all Message-Ids are
properly composed with unique hashes, which causes matches on two
completely different messages.  This causes unique messages to get
lost or discarded, which is a nasty side effect that compels most
people to not use it at all.

> > In this case, you did a reply-all and I received a personal copy
> > from you in my personal inbox because the list headers were
> > missing, so it was not properly filtered. 
> 
> This is also why you should base your filtering on To/Cc and not on
> non-standardized headers.

Filtering on TO and CC doesn't work, because the list address is not
necessarily in those headers.  Anyone can put whatever they want in
those headers.  It's also haphazard because the filter must then be
aware of all the address aliases and ways to specify it.

There are some lists out there running on unsophisticated home-grown
MLM tools, where there are no list headers, and users are forced to
crudely filter on TO and CC fields.  Everytime someone posts using BCC
field on these lists, the message does not get filtered - and that's
not just a problem on replies to ones own posts, but all posts from
anyone using BCC.

Using the List-Id field is reliable because no matter how a message
makes it to the list, the list software will put this header on every
message and compose the field the same.  This field is standard on all
lists that use majordomo or mailman MLM software, and covered by
RFC2919.  (see "Alternatives to the ^TO_ Macro" at 
http://tinyurl.com/ybrhlsj )

> By forcing a Reply-To to the list you also make it MUCH HARDER to
> allow someone to reply privately if they want to.  It's quite
> annoying when I want to send a personal reply but I can't because
> when I hit reply it forces it to go back to the list.

I agree.  I am certainly not advocating putting a list address in the
Reply-To field.  That would be an abuse of the purpose of that field,
which exists solely to specify where private replies are to be
directed, if different from the FROM field.  It is rightly a rarely
used field, because most people want private replies to go to the FROM
address.

> *I* know better than the administrator as to whom I want to send my
> messages.  Don't force me to send to the list when I don't want to.
> Indeed, this is exactly why we encourage Reply-To-List usage.
> 
> Personally, yes, I use Reply-All.

Folks with broken or deficient mail clients use Reply-All for lack of
a proper Reply-To-List feature.  It's not something that should be
encouraged, because users with these kind of deficient MUAs tend not
to have good filtering themselves, and are generally unaware of the
issues caused by not cleaning up the header to just contain the list
address.  Simply encouraging the use of Reply-All is in effect saying:
it's okay to be lazy, and send copies everywhere, and let everyone
else sort it out.  

If you only encourage Reply-To-List, users who don't have that feature
will figure out that they need to Reply-All, and then clean up the
header.  Otherwise they'll simply think it's proper to ignore
Mail-Followup-To header, and that it's okay to send everyone
unrequested personal copies.