Hi,

On Sat, Jun 13, 2015 at 02:47:00PM -0400, Xu Wang wrote:
> 
> Is it possible to search based on which message ID a message
> *responds* to? For example, suppose message id is MESSAGEID. I want to
> find all emails that responded to MESSAGEID. How to enter such a query
> into notmuch?

AFAIK, this is not possible.  Notmuch does not allow searching special
headers.  You could probably write a script using the threads output
format to get the thread, and then use formail to find the responses.

I however think you are probably approaching the problem incorrectly,
but that's just a guess.  More information about what is your goal and
why, would help.  Maybe there is another way to achieve what you want to
achieve.

Hope this helps,

-- 
Suvayu

Open source is the future. It sets us free.