Changing the subject

[Amedee Van Gasse]

On 27-02-10 22:05, Christian Schult wrote:

> That's not subject changing (in a thread), that's simply starting a _new_ thread.
> If you start a new thread, there's no need to capture any old subject.

If you change the subject in a thread, is it still part of the thread? I 
mean, apart from whatever any header says and how it is interpreted by 
whatever mail client.
Because, if it is still part of the thread, you aren't really talking 
about something else, so why bother to change the subject header because 
you're not changing the subject at all.