[Users] Message-ID

[Rich Pieri]

On Fri, 1 Feb 2013 01:25:36 +0000
RW <rwmaillists at googlemail.com> wrote:

> How is that consistent with your statement that "Message-IDs are not
> necessary for threading"? How do you identify the first message in a
> thread without looking at its Message-ID header?

The first message of a thread will have no In-Reply-To or References
headers. Children of this parent may have references to it in their
In-Reply-To and References headers. This is not required by RFCs 822
and 2822. From this point on you really should look at JWZ's threading
algorithm.

-- 
Rich P.