To allow a Mail-client to Thread email, it puts a special header line in the email. When a similar Mail-client responds, it recognizes the special header and maintains that special header in any response. Sometimes a Mail-client adds it's own header that specifically says: In response to Message-xxxxx.

The problem is that different Mail-clients use different headers for determining if a mail is a response or not. Eudora is very robust in handling various different "standards", and often can thread mail fairly well. On the other hand, Outlook is fairly poor and doesn't even recognize other MS threading "standards" - or for that matter the threading "standards" of other versions of Outlook.

Outlook also wipes out any identifying header information when it creates the header for a responding message.

I hope that explains why most Admins treat threading email in Outlook as a joke.

I'm not aware of a IEEE standard's RFC that covers the threading of email. I'm sure there is one, but the major makers of email clients seem to be ignoring it.

Jon Carnes

On Mon, 2003-06-30 at 20:36, jsmith wrote:

I have posted over and over that this issue is not just Outlook or MS related. I have the same issue with headers and footers regardless of what email client is used. I have 2.1.2 on a freebsd 4.7 machine with sendmail. My mac users send to the list, Eudora users, outlook and all I have tried. Same problem.

I am not saying its not more prevalent in outlook. But it is happening with other programs. And I know everyone will be quick to say, don't use sendmail, or you must have installed it wrong.

I have posted the problem here before and no one has responded with anything close to a resolution. I was told by someone that it was being address in the next version. So I am waiting.

There doesn't seem to be nothing else I can do.

As far as the statement to use a MUA that doesn't suck. You need to crawl out of the 18th century. MS has had the mail client world tied up for a long time, and gains more everyday. I personally don't like Outlook in a pop3 environment. But in an exchange environment protected by a proper firewall there is only a few that compare for collaboration and global use. But then again, I come from an environment that has servers all over the world synchronizing the GAL and shared objects every night. Not too many other options for global address books. There are some. But not many.

My little 2 cents

-----Original Message----- From: Will Yardley [mailto:william+mm@hq.newdream.net] Sent: Monday, June 30, 2003 4:53 PM To: mailman-users@python.org Subject: [Mailman-Users] Re: Flat Threads when posting usingOutlook/Exchange clients

On Mon, Jun 30, 2003 at 03:56:59PM -0700, Roy Santos wrote:

...

I have seen a few postings regarding problems getting flat threads while posting using Outlook clients. See http://www.mail-archive.com/mailman-users@python.org/msg03011.html. But what I haven't seen is an answer on how or what needs adjusting in MS for making proper threading that Netscape, Eudora, Mozilla, etc.

What needs adjusting? Using an MUA which doesn't suck.... I think some versions of Outlook do generate the proper headers, but I imagine it's based on version #, as opposed to being a configurable setting. The Mac version (which is much better behaved in general) does.

...

Is there a setting in the Defaults.py or other place to use "Subject" instead of "In-Reply-To" or "References"?

I'm pretty sure there isn't. A lot of MUAs can do this; it probably wouldn't be a bad idea, but could cause unexpected problems (like when people send messages to the list with generic subject lines).

At 5:36 PM -0700 2003/06/30, jsmith wrote:

I have posted over and over that this issue is not just Outlook or MS related. I have the same issue with headers and footers regardless of what email client is used. I have 2.1.2 on a freebsd 4.7 machine with sendmail. My mac users send to the list, Eudora users, outlook and all I have tried. Same problem.

Lack of proper headers (or headers being improperly formatted) is 

usually caused by the MUA. However, in your case, it would seem that the cause may be an MTA between your server and your clients, which is causing headers to be incorrectly munged.

I am not saying its not more prevalent in outlook. But it is happening with other programs. And I know everyone will be quick to say, don't use sendmail, or you must have installed it wrong.

Sendmail will not cause these problems, unless you (or someone 

else) severely mis-configured it to do so. Same with postfix or Exim. I can imagine that certain types of anti-virus and/or anti-spam processing engines might cause problems like this, or they might be caused by other MTAs that handle the mail before your mailing list server receives the messages.

As far as the statement to use a MUA that doesn't suck. You need to crawl out of the 18th century. MS has had the mail client world tied up for a long time, and gains more everyday. I personally don't like Outlook in a pop3 environment. But in an exchange environment protected by a proper firewall there is only a few that compare for collaboration and global use. But then again, I come from an environment that has servers all over the world synchronizing the GAL and shared objects every night. Not too many other options for global address books. There are some. But not many.

Yes, in a pure Microsoft-only environment, using Microsoft 

products to access Microsoft services on Microsoft servers, and totally isolated from the real world, and where Microsoft is your One True Yardstick of All Perfection, I can understand how you could potentially come to this conclusion.

Otherwise, I'd suggest that you start looking for SPOFs (Single 

Points of Failure) where all mail coming into your mailing list or leaving your mailing list is processed through the same server (or set of servers all configured identically), or at least where all the mail messages exhibiting the "flat thread" problem pass through one server (or set of identically configured servers) whereas unaffected messages take a different route.

As an Internet mail systems professional with over ten years 

experience in the field (including two years as the Sr. Internet Mail Administrator for AOL), and many years experience using and managing mailing lists with a variety of packages (not to mention years of experience administering various LAN e-mail packages), I believe that I can safely say that there is not likely to be anything that would cause the kind of problems that you're talking about with regards to FreeBSD or sendmail, and I certainly haven't seen these kinds of problems with mailman 2.1.2.

So, it seems to me that you need to get back to basics.  Find out 

what is common between all the mail messages that exhibit the problem, and which is not found in the messages which are clean, and you most likely have found the root cause.

--

Brad Knowles, <brad@stop.mail-abuse.org>

"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." -Benjamin Franklin, Historical Review of Pennsylvania.