On 2013–01–30 Keith J. Schultz wrote:

> > First I would like to ask not to change messages' subject if you want to see another point.
> > Changing subject breaks the normal links of threads, further it becomes very difficult to find a message embedded in another subject.
> > For a new subject create a new message/thread.
> 	1) I was not aware that in the headers that information of the message I hit the reply button on.

There's a reason that mail clients provide two distinct features for
“new mail” and “reply to”. A new mail creates a new thread and a
reply to creates an “In-Reply-To:” header.

> 	2) I would assume that e-mail clients and forums would be smart enough to check the
> 	     subject like and react appropriately.  

You sent a message containing:

  In-Reply-To: <9CBFD630-FEFD-4F75-9E3C-D6BA53B27FF5@web.de>

And that's exactly how email clients should display the message, as
a reply to the message with the given Message-ID. It's totally valid
to change the “Subject” line keeping the thread. An email client has
no built-in crystal ball which could prophesy your intentions.

>   At least my e-mail client handles these things gracefully.

I would consider filing a bug report.


Marco