On Tuesday 08 of September 2020 00:45:27 Steven D'Aprano via tde-users 

wrote:

On Sun, Sep 06, 2020 at 02:46:58PM -0700, William Morder via tde-users 

wrote:

So the short version is: only hit reply if you intend to keep the

topic within the thread.

If we go off-topic, then we ought to create a brand-new email, not

just hit replay; otherwise, we drag email addresses and related

threads upon threads in, and we end up with 293 comments (I hear, but

haven't seen them myself).

The new archive can track threads in detail. Therefore, a thread emerged 

here, which began in 2018 and was confused in this way.

Therefore, it is a good idea to follow a simple rule that a new thread must 

start as a new message, not in response to some unrelated message in which 

the subject and content will be replaced.