[offtopic] Gmail "conversations" splitting up from time to time

[Philippe Vaucher]

Hello,

I noticed that my Gmail threads started to be all split up.

I traced this to some clients change the subject line to "RE: foo"
instead of "Re: foo" like this other clients.

Drew, I think in all my cases it comes from your client :-/ Is there
something you can do to fix this? Or GMail users, do you know of a
fix?

This is visible on
https://lists.gnu.org/archive/html/emacs-devel/2020-05/threads.html,
we see that Drew's messages are with "RE" but the mailing list
software is not as broken as Gmail.

This is annoying because it's then hard to follow a thread properly.