Understanding the "replied" tag

[Xu Wang]

On Thu, Jun 11, 2015 at 2:25 PM, Jani Nikula <jani at nikula.org> wrote:
> On Thu, 11 Jun 2015, Xu Wang <xuwang762 at gmail.com> wrote:
>> Dear all,
>>
>> First, I am extremely excited to be a part of this list now. notmuch
>> has really helped me. Thank you go all individuals working to improve
>> it and to help others to know how to use it.
>>
>> I would really like to know if a message has been replied to (e.g.
>> using a certain message id). It seems that all I need to do is check
>> for the "replied" tag. But often this tag is not there, even when
>> there has been a reply (I have confirmed this through the thread
>> display and checking the message that replied to the message to make
>> sure it indeed has header "replied-to:<MSG-ID>").
>>
>> I have looked in mutt, and also I see many situations where there is
>> no 'r' flag, especially for emails sent from me.
>>
>> The following returns true:
>> notmuch config get maildir.synchronize_flags
>>
>> So at least both are giving same answer, but I'm not sure why not
>> saying "replied" thread is correct.
>>
>> What is incorrect for my way of thinking about "replied"? Do I
>> misunderstand what it is supposed to do or am I not updating the flags
>> correctly?
>
> Notmuch deals with the "replied" tag in two ways.
>
> First, the tag is synchronized with the maildir flag R, both ways. This
> is the "R" in the filename after ":2,". See [1] for details.
>
> Second, the notmuch-emacs interface adds the "replied" tag upon sending
> the reply. You can customize this tag, but note that only "replied" gets
> synchronized to maildir flags.
>
> If you use a MUA that doesn't either add the R flag or call notmuch to
> add the "replied" tag, you'll lose this bit of information.
>
> You might also find [2] relevant.
>
> BR,
> Jani.
>
>
> [1] http://cr.yp.to/proto/maildir.html
> [2] http://notmuchmail.org/special-tags/

Thank you so much, Jani. This is very informative to me. I think I
have a good understanding now of what is going on.

My question then is this:

I trust notmuch more than mutt, because notmuch is aware of threads
and all mail boxes. Also note that I often use gmail web interface to
reply emails.

Am I correct in the following: if notmuch wanted to, when I run
"notmuch new", notmuch has the information that it could
(theoretically) update and correct all of the "replied" tags. Is that
correct? If so, my next question is: why doesn't it do that?

I think I'm close to getting notmuch intution on its goals.

Kind regards,

Xu