Re: nnimap gmail "A T" and "^" not working

[Andrew Cohen]

>>>>> "J" == JibStyle  <jibstyle209@gmail.com> writes:

    J> Andrew Cohen <acohen@ust.hk> writes:
    >> gmail's imap implementation is non-standard and the standard
    >> thread-referral search doesn't seem to work properly (I never
    >> noticed this before since most of email activity is not in
    >> gmail).

[...]

    J> Thanks for clarifying :) I am glad I did not shoot myself in the
    J> foot, as the manual specified is possible.

I tried poking around a bit more and maybe I was too hasty in blaming
gmail :)

For me, the failure of "A T" is arising because the 'references header
in the emails within a thread are not right. In particular, this header
is supposed to include most of the message-ids in the thread that the
message is aware of (e.g. if its the 4th message in a chain of replies
this header should contain the message-ids of all the prior messages; if
this list of prior messages is extremely long the spec allows dropping
part of it). But for the cases where "A T" fails this header contains
only a /single/ message-id, that of the immediate prior email. This
prevents the full thread from being found.

The most likely explanation is that the mailer used by the sender is not
adding the full references header. I assumed it was gmail that was
responsible, but a closer look at the messages on which "A T" fails
shows that they were all sent by the iphone mailer. So while I haven't
done any exhaustive testing, this is my current culprit.  But I am
curious if others are seeing the same thing. 

So  jibstyle maybe you can help with some testing? First, for the
purposes of the test can you
1. Set 'gnus-refer-thread-use-search to 'nil,
2. Enter the "[Gmail]/All Mail" group and find an article late in the
thread on which you know thread referral fails to find the full thread.
Examine the headers of this article (by typing C-g when point is on the
article in the summary buffer) and see what is in the  References
header? And what mailer was used to send the message?

For example when I do this I find the headers contain

In-Reply-To: <CAKfuin7MPjj5m@mail.gmail.com>
References: <CAKfuin7MPjj5m@mail.gmail.com>
X-Mailer: iPhone Mail (19E258)

which shows that the References header only contains the immediately
prior email's message-id but not that of any of the other messages.

Best,
Andy
-- 
Andrew Cohen