ask notmuch to find back "reply-to's"

[Daniel Kahn Gillmor]

On Sat 2016-07-02 20:28:41 -0400, Xu Wang wrote:
> Hello all,
>
> I have a situation where sometimes I sync a later message. For
> example, the following happens on times:
>
> 1a. sync message 1.
> 1b. not much new
> 2a. sync message 3 (which replied to message 2)
> 2b. not much new
> 3. sync message 2 (which replied to message 1)
> 3b. not much new
>
> This happens because of my workflow of offlineimap. It takes a long
> time to sync some folders so often I prefer to skip, but sometimes
> they contain replies.

on most systems, assuming standard headers, notmuch should indeed
assemble these into the same thread.

the relevant headers are In-Reply-To and References.

Can you show those headers for this example?  If they have these message-IDs:

 message 1: XXX
 message 2: YYY
 message 3: ZZZ

then i'd expect the following headers:

 message 1:
   Message-Id: XXX
    <no In-Reply-To or References>
 message 2:
   Message-Id: YYY
   In-Reply-To: XXX
   References: XXX
 message 3:
   Message-Id: ZZZ
   In-Reply-To: YYY
   References: XXX, YYY


If notmuch has indexed them all, they should all be part of the same
thread.

        --dkg