[Mailman-Users] How to properly nest a response from Gmail

[BA lanfest]

MUCH thanks for the reply Mark.  I've been looking for help everywhere and
yours is the first response I've received.  I was referring to the archived
view threading on the web.

Another possibility is a reply get's sent to you and then resent to the
> list as a separate message. If you reply to the copy sent to you, your
> reply is not a reply to the message in the list archive so it isn't
> threaded as such.
>

I am pretty sure this is what happened.  When I replied to the first
message (which did not thread correctly), my subscription mode was digest
only so I was not getting individual messages, but I did get a message in
my inbox from the member I wanted to respond to, because he mailed me a
separate copy.  I replied to that, and I'm guessing like you said it had a
different Message-ID.

Later I changed my subscription to non-digest mode, and then when I replied
to one of those that I received (i.e. a message actually sent to the list
and not just me), it did thread properly.

However, the absolute weirdest thing is this.  Yesterday, I signed up for a
few other lists to run some tests.  One thing I tried was responding to an
archive message straight from the web using the <a href="mailto:someone">
link at the top of a message (my browser is configured to compose a Gmail
message when I click a link like that).  The first thing I noticed was that
even though that href link appears to ask your mail client to add an
"In-Reply-To" header, Gmail does not actually recognize that request, and
the Gmail message I sent to the list had no "In-Reply-To" header at all.
 However... the archive view STILL threaded my reply correctly, even
without that header!  So I went back to my "real list" and tried this same
thing, and it did not in fact work on this list (using the web reply link).
 So.. I do know now how to get my responses to thread properly on my real
list (I must have received a real copy in my inbox and reply to it from
there), but it is more of an academic curiosity why on some other list I
found, the threading still works even in the complete absence of
"In-Reply-To" headers.

Thanks again.

On the "test list" I was using