[sf-perl] Admin: Duplicate copies of messages

Vicki Brown vlb at cfcl.com
Fri Dec 16 14:20:52 PST 2005

I am replying to the list here, (not to all :-) rather than to Josh only.
I am doing this because Josh has raised an unfortunately common
misunderstanding about email and mailing lists.

Getting technical....

At 13:21 -0800 12/16/2005, Josh Berkus wrote:
>Per my private e-mail ... the list is actually not configured with
>reply-to-list, or it's not working.   Here's the mail header:
At 13:21 -0800 12/16/2005, Josh Berkus wrote:
>In-Reply-To: <200512161235.11586.josh at agliodbs.com>
> <Pine.LNX.4.44.0512160924290.25461-100000 at cumulonimbus.cloudfactory.org>
> <p0623092abfc8cca3ab6d@[]>
> <200512161235.11586.josh at agliodbs.com>
>X-Mailer: Eudora for Macintosh!
>Date: Fri, 16 Dec 2005 12:49:39 -0800
>To: josh at agliodbs.com,
> sanfrancisco-pm at pm.org
>From: Vicki Brown <vlb at cfcl.com>
>Subject: Re: [sf-perl] Duplicate copies of messages
>Content-Type: text/plain;
>  charset="us-ascii"

Yes, that is a mail header.
No,  it is not the header from the sanfrancisco-pm at pm.org list.
(Trust me on this one. I configured the list. I know how it is set up. ;-)

Note the headers above _carefully_.
You'll see that I
  From: Vicki Brown <vlb at cfcl.com>
sent a message to two recipients:
  To: josh at agliodbs.com,
      sanfrancisco-pm at pm.org

Therefore, two _separate_ instances of the message were generated and they
went their separate ways.

Because Josh == josh at agliodbs.com &&
        Josh is also (coincidentally) subscribed to sanfrancisco-pm at pm.org
       Josh received TWO (separate) pieces of mail.

Depending upon the configuration of your email server and client, you may or
may not actually see both pieces of mail in your inbox. Some clients can
delete "identical" messages.

The mail message from which the above headers where clipped is the personal
message from vlb at cfcl.com to josh at agliodbs.com - only Josh received this one.

It is NOT the list message from vlb at cfcl.com to sanfrancisco-pm at pm.org.
Headers on the latter look like this:

>List-Id: San Francisco Perl Mongers User Group <sanfrancisco-pm.pm.org>
>List-Unsubscribe: <http://mail.pm.org/mailman/listinfo/sanfrancisco-pm>,
>	<mailto:sanfrancisco-pm-request at pm.org?subject=unsubscribe>
>List-Archive: <http://mail.pm.org/pipermail/sanfrancisco-pm>
>List-Post: <mailto:sanfrancisco-pm at pm.org>
>Sender: sanfrancisco-pm-bounces at pm.org

This confusion over which piece of mail is which and how it was sent is one
of only many problems people have with email lists. It also plays as an
excellent example of WHY it's a bad idea to "reply all" to an email list.
Reply to all will send duplicates to at least one person (iff the sender is
also a subscriber). As more individuals are added to the To: and Cc: lines,
Reply all will send more and more duplicate mail.

I ran into this same problem a while back on another list. In that case, a
member did a "reply all" (including me) and I responded directly to the
personal message, inadvertently taking a conversation offline.

Train yourself. Take responsibility for how you address the email you send.
Do not reply all to a list (unless you really really meant to do that).
Do not Reply all to mail with a Reply-to header.
Re-read your headers before sending mail.

Consider this a learning experience.

- Vicki

  zzZ                   San Francisco Bay Area, CA
 z  |\     _,,,---,,_   Books, Cats, Tech
zz /,`.-'`'    -.  ;-;;,_  http://cfcl.com/vlb
  |,4-  ) )-,_. ,\ ( `'-'  http://heatercats.com
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