*HCS* Final Call for Ignitaries!

britt britt at bolen.com
Mon Oct 2 16:08:35 EDT 2000

I'm talking taht the policy is not broken, how the policy of "all mail
should be sent to the list" is implemented technically (in this case
munging-reply-to) is not the issue i was addressing.

as no-longer-the-guy-with-root-on-lists.hcs i don't care about the
technical issue :)


On Mon, 2 Oct 2000, Brendan Connell wrote:

> On Mon, 2 Oct 2000, britt wrote:
> > uh, no it's not broken.
> <reels in bait>
> Oh, yes it is.  Admittedly, this is the subject of numerous flamewars...
> but munging the Reply-to: line really IS a Bad Idea (TM).  If you're not
> convinced, here's one of the best cases I've seen made against it...
> ===========================================================================
> http://www.unicom.com/pw/reply-to-harmful.html
>                     ``Reply-To'' Munging Considered Harmful
> An Earnest Plea to Mailing List Administrators
>      _________________________________________________________________
>    An email message requires some amount of processing when it is
>    redistributed to a mailing list. At the very least, the envelope must
>    be rewritten to redirect bounces directly to the list administrator.
>    While the message is being processed, the list administrator might
>    take advantage of the opportunity to munge some of the message
>    headers.
>    Some forms of header munging are helpful, such as special
>    loop-detection headers. Others are questionable. Most are ill-advised
>    or dangerous. Many list adminstrators want to add a Reply-To header
>    that points back to the list. This transformation also is one of the
>    most ill-advised.
>    Some administrators claim that Reply-To munging makes it easier for
>    users to respond to the entire list, and helps encourage list traffic.
>    These benefits are fallacious. Moreover, Reply-To can have harmful --
>    even dangerous -- effects. If you think Reply-To munging is a good
>    idea, I hope I can change your mind.
> The Principle of Minimal Munging
>    Email processing is pretty tricky. Read through RFC-822, the Standard
>    for the Format of ARPA Internet Text Messages, sometime. It is 47
>    pages of dense, dry detail. A lot of engineering and consideration
>    went into this work. Even still, RFC-822 leaves many corner conditions
>    and specialized circumstances poorly specified. RFC-1123, the
>    commonly-called Internet Host Requirements document, adds a couple
>    dozen more pages, and remedies some of the defects. Then there is
>    MIME, X.400 mapping, and a handful of other standards and conventions
>    -- some documented and some folklore. Email handling is surprisingly
>    complicated, and even an innocuous-sounding change might have grave,
>    unintended consequences.
>    The ``Principle of Minimal Munging'' is a good rule that will keep you
>    out of trouble. It says you should not make any changes to an email
>    header unless you know precisely what you want to do, why you want to
>    do it, and what it will affect. Unless you can articulate a clear
>    reason for munging and understand the full consequences of the action,
>    you should not do it.
>    The ``Principle of Minimal Munging'' will help you avoid the sorts of
>    problems we are about to discuss. This principle is a rule designed to
>    be broken, but you can avoid some significant heartache by thinking
>    hard and long before you do so.
> It Adds Nothing
>    Reply-To munging does not benefit the user with a reasonable mailer.
>    People want to munge Reply-To headers to make ``reply back to the
>    list'' easy. But it already is easy. Reasonable mail programs have two
>    separate ``reply'' commands: one that replies directly to the author
>    of a message, and another that replies to the author plus all of the
>    list recipients. Even the lowly Berkeley Mail command has had this for
>    about a decade.
>    Any reasonable, modern mailer provides this feature. I prefer the Elm
>    mailer. It has separate ``r)eply'' and ``g)roup-reply'' commands. If I
>    want to reply to the author of a message, I strike the ``r'' key. If I
>    want to send a reply to the entire list, I hit ``g'' instead. Piece 'o
>    cake.
>    I mention Elm here (and a lot later on) simply because that's the
>    mailer I use everyday. This sort of support is not unique to Elm Any
>    reasonable mailer provides it. The Pine mailer, for instance, asks
>    directly, ``Reply to all recipients?'' when you use the ``r'' command.
>    It doesn't get much easier than that!
>    Whichever mailer you choose, please read the fine manual that comes
>    with it. Unless you are stuck with some decrepit mail system, I bet
>    you'll find it has a similar feature. If so, you easily can choose to
>    direct your responses either to the original author or the entire
>    list. Mauling the mail headers doesn't make it any easier.
> It Makes Things Break
>    If you use a reasonable mailer, Reply-To munging does not provide any
>    new functionality. It, in fact, decreases functionality. Reply-To
>    munging destroys the ``reply-to-author'' capability. Munging makes
>    this command act effectively the same as the ``reply-to-group''
>    function. We haven't added anything new, we've only taken away.
>    Reply-To munging is not merely benign, it is harmful. It renders a
>    useful mail capability inoperative.
> Freedom of Choice
>    Some administrators justify Reply-To munging by saying, ``All
>    responses should go directly to the list anyway.'' This is arrogant.
>    You should allow me to decide exactly how I wish to respond to a
>    message. If I feel a public response is justified, I'll hit the ``g''
>    key and tell Elm to do a group-reply. If I believe a private response
>    is more appropriate, I'll use ``r'' to send one. Please allow me the
>    freedom to decide how to handle a message.
> Can't Find My Way Back Home
>    It may be impossible to reply to the author of a message once the
>    Reply-To header is munged. The Reply-To header was not invented on a
>    whim. It is there for the sender of a mail message to use. If you
>    stomp on this header, you can lose important information.
>    There are good reasons why the sender might insert a Reply-To header.
>    The sender might not be the original author of the message (the name
>    that appears in the From header). If responses should return to the
>    sender and not the original author, then the sender will insert a
>    Reply-To header. Or, maybe the sender added a Reply-To because he or
>    she cannot receive email at the account from which the message was
>    sent. There are many good reasons to place a Reply-To header into a
>    mailing list message.
>    If the Reply-To is munged by the mailing list, the value provided by
>    the original sender is lost. Reply-To munging can make it impossible
>    to reach the sender of a message.
> Coddling the Brain-Dead, Penalizing the Conscientious
>    There are, unfortunately, poorly implemented mail programs that lack
>    separate reply-to-author and reply-to-group functions. A user saddled
>    with such a brain-dead mailer can benefit from Reply-To munging. It
>    makes it easier for him or her to send responses directly to the list.
>    This change, however, penalizes the conscientious person that uses a
>    reasonable mailer. This is a poor trade-off. As Internet list
>    administrators, we should encourage people to run reasonable software.
>    If a few people need to type in a full reply address so that everybody
>    else can use all the features of their mailer, I say, ``Fine!'' We
>    should not penalize the conscientious to coddle those who run
>    brain-dead software.
> Principle of Least Work
>    Compare and contrast: the work required for me (or any other Elm user)
>    to reply on lists that do and don't employ Reply-To munging.
>                 Case One:               Case Two:
> Action          Without Munging         With Munging
> =============   =====================   =====================
> Reply to        Hit the "g"             Probably hit the "r"
> everybody.      key.                    key, but maybe the "g"
>                                         key if there were other
>                                         recipients of the message.
> Reply just      Hit the "r"             Look at the original
> to author.      key.                    message header, write
>                                         down the sender's
>                                         email address, hit the
>                                         "r" key, call up the
>                                         header editing menu,
>                                         erase the current To:
>                                         value, and type in the
>                                         sender's full email
>                                         address.  And pray the
>                                         correct address wasn't
>                                         wiped out when the Reply-To
>                                         was munged.
>    Again, your preferred mailer probably implements this feature in a
>    different fashion. Nonetheless, it should be easy. I'll take box
>    number one, Monte.
> Principle of Least Surprise
>    When I hit the ``r'' key in Elm, it sends a response to the author of
>    a message. When you munge the Reply-To header you change this action
>    so that it does something entirely different from what I expect. This
>    creates specialized behavior for your mailing list, which increases
>    the potential for surprise. I'm not schooled in the science of human
>    factors, but I suspect surprise is not an element of a robust user
>    interface.
>    Private messages frequently are broadcast across lists that do
>    Reply-To munging. That's an empirical fact. It's what happens when you
>    violate the principle of least surprise.
> Principle of Least Damage
>    Consider the damage when things go awry. If you do not munge the
>    Reply-To header and a list subscriber accidentally sends a response
>    via private email instead of to the list, he or she has to follow up
>    with a message that says, ``Ooops! I meant to send that to the list.
>    Could you please forward a copy for me.'' That's a hassle, and it
>    happens from time to time.
>    What happens, however, when a person mistakenly broadcasts a private
>    message to the entire list? If the message is a complaint about the
>    personal hygiene of sender's boss, or the sex life of his or her
>    roommate, a simple ``Ooops!'' won't cut it. About all you can do is
>    send a followup with lots of retroactive smileys (weak). Or say your
>    cat was dancing on the keyboard (better). Or start reading the
>    classifieds for a new job/roommate/set of teeth (most likely).
>    Reply-To munging encourages catastrophic failure modes. Sure, you
>    don't need Reply-To munging to create this sort of damage. A simple
>    slip of the fingers will suffice. When, however, you violate the
>    ``Principle of Least Surprise'' you invite this sort of disaster. A
>    responsible list administrator will avoid creating avenues that lead
>    to such extreme damage.
> And in the End...
>    If you are not convinced yet, then allow me one final plea. I
>    contribute to the Elm mailer development team. I get to see a lot of
>    the wants and requests from the user community. Guess what feature
>    more and more people are asking for? A third reply command -- one that
>    ignores any existing Reply-To header! Want to guess why people are
>    asking for it? If you think you are doing your subscribers a service
>    by munging Reply-To headers, you are kidding yourself. You are making
>    your subscribers miserable.
>    Some list administrators, even after reading all this, seem to say,
>    ``Oh, it's not that bad. Besides, my subscribers like it!'' If they
>    do, it's probably because they haven't bothered to learn to use the
>    ``reply-to-group'' feature of their mailer. Instead of going through
>    all the trouble of making your list gateway scribble on email headers,
>    how about making an effort to educate your subscribers?
> Summary
>    Many people want to munge Reply-To headers. They believe it makes
>    reply-to-list easier, and it encourages more list traffic. It really
>    does neither, and is a very poor idea. Reply-To munging suffers from
>    the following problems:
>      * It violates the principle of minimal munging.
>      * It provides no benefit to the user of a reasonable mailer.
>      * It limits a subscriber's freedom to choose how he or she will
>        direct a response.
>      * It actually reduces functionality for the user of a reasonable
>        mailer.
>      * It removes important information, which can make it impossible to
>        get back to the message sender.
>      * It penalizes the person with a reasonable mailer in order to
>        coddle those running brain-dead software.
>      * It violates the principle of least work because complicates the
>        procedure for replying to messages.
>      * It violates the principle of least surprise because it changes the
>        way a mailer works.
>      * It violates the principle of least damage, and it encourages a
>        failure mode that can be extremely embarrassing -- or worse.
>      * Your subscribers don't want you to do it. Or, at least the ones
>        who have bothered to read the docs for their mailer don't want you
>        to do it.
> Addendum
>    In case you are wondering, yes, I once thought Reply-To munging was a
>    nifty idea. I got better though.
>    When I started running email lists, I munged 'em all. One day I
>    accidentally sent a private, personal reply out over one of my own
>    damn lists. If the list owner can't remember how to use the list
>    properly, no way will the subscribers be able to sort it out. I
>    stopped munging the very next day.
>    On the whole, it has worked out quite well. Yes, on occasion somebody
>    mistakenly responds directly to the author of a message when they
>    wanted to reply to the group. Most folks, however, seem to catch on
>    pretty fast to how it works, and seem to appreciate the flexibility.
>    Moreover, private responses mistakenly sent to the entire list have
>    become an almost unheard-of event.
>      _________________________________________________________________
> What do You Think?
>    Leave your comments and see what others say in the discussion forum.
>      _________________________________________________________________
>     Chip Rosenthal
>     <chip at unicom.com>
>    Back to the Paperware Archive.
>    Up to Unicom Systems home page.
>    Let us know your comments, corrections, additions, suggestions.
> $Id: reply-to-harmful.html,v 1.17 1999/01/05 09:08:03 chip Exp $
> $Log: reply-to-harmful.html,v $
> # Revision 1.17  1999/01/05  09:08:03  chip
> # fixed links to RFCs
> # started logging modification history
> #
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Britt Bolen               britt at bolen.com               britt.bolen.com 

"Aah, for the days when aviation was a gentleman's pursuit - back before 
every Joe Sweatsock could wedge himself behind a lunch tray and jet off 
to Raleigh-Durham."  --- Sideshow Bob

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