Hi,

I recently started using another IMAP MUA (Thunderbird), and noticed that
Thunderbird has couple of messages that are missing in Gnus, or never showed
up there.

I'm running Emacs HEAD revision 49a42fb[1] on FreeBSD 11.1.

Following is an excerpt (with carriage returns at the end, replaced by ^M)
from the *nnimap log* for a search query I attempted where I expected to see
the message I was hoping for:

--8<---------------cut here---------------start------------->8---
21:09:38 [mail.domain.tld] 798 SELECT "freebsd/inbox"^M
21:09:39 [mail.domain.tld] 799 UID SEARCH SUBJECT "bsd.emacs.mk"^M
21:09:39 [mail.domain.tld] 800 SELECT "freebsd/inbox"^M
21:09:39 [mail.domain.tld] 801 UID FETCH 625:627,646:647,741,748:749,934:935,963,970,989:990,1402:1403,4559,4968,8461:8464,8481:8482,8628,8630,8647,9105:9107 (UID RFC822.SIZE BODYSTRUCTURE BODY.PEEK[HEADER.FIELDS (Subject From Date Message-Id References In-Reply-To Xref X-Spam-Status X-Bogosity X-CRM114-Status To Newsgroups Cc)])^M
--8<---------------cut here---------------end--------------->8---

Following is an excerpt from the IMAP session to the mail server performed
using telnet using the same IMAP commands as nnimap:

--8<---------------cut here---------------start------------->8---
a1 SELECT "freebsd/inbox"
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft gnus-expire Junk NonJunk)
* OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft gnus-expire Junk NonJunk \*)] Flags permitted.
* 5921 EXISTS
* 0 RECENT
* OK [UIDVALIDITY 1293092904] UIDs valid
* OK [UIDNEXT 72815] Predicted next UID
* OK [HIGHESTMODSEQ 9319] Highest
a1 OK [READ-WRITE] Select completed (0.001 + 0.000 secs).
a02 UID SEARCH SUBJECT "bsd.emacs.mk"
* SEARCH 625 626 627 646 647 741 748 749 934 935 963 970 989 990 1402 1403 4559 4968 8461 8462 8463 8464 8481 8482 8628 8630 8647 9105 9106 9107 72814
a02 OK Search completed (0.071 + 0.000 + 0.070 secs).
--8<---------------cut here---------------end--------------->8---

Please note that UID 72814 is missing from Gnus' UID FETCH command.

As the mail server (Dovecot 2.2.32) in question is maintained by me, I ran
server-side search using doveadm, and following is what I get:

--8<---------------cut here---------------start------------->8---
% doveadm search mailbox freebsd/inbox subject "bsd.emacs.mk"                
deb33d369d2d2c516894000057b68ab5 625
deb33d369d2d2c516894000057b68ab5 626
deb33d369d2d2c516894000057b68ab5 627
deb33d369d2d2c516894000057b68ab5 646
deb33d369d2d2c516894000057b68ab5 647
deb33d369d2d2c516894000057b68ab5 741
deb33d369d2d2c516894000057b68ab5 748
deb33d369d2d2c516894000057b68ab5 749
deb33d369d2d2c516894000057b68ab5 934
deb33d369d2d2c516894000057b68ab5 935
deb33d369d2d2c516894000057b68ab5 963
deb33d369d2d2c516894000057b68ab5 970
deb33d369d2d2c516894000057b68ab5 989
deb33d369d2d2c516894000057b68ab5 990
deb33d369d2d2c516894000057b68ab5 1402
deb33d369d2d2c516894000057b68ab5 1403
deb33d369d2d2c516894000057b68ab5 4559
deb33d369d2d2c516894000057b68ab5 4968
deb33d369d2d2c516894000057b68ab5 8461
deb33d369d2d2c516894000057b68ab5 8462
deb33d369d2d2c516894000057b68ab5 8463
deb33d369d2d2c516894000057b68ab5 8464
deb33d369d2d2c516894000057b68ab5 8481
deb33d369d2d2c516894000057b68ab5 8482
deb33d369d2d2c516894000057b68ab5 8628
deb33d369d2d2c516894000057b68ab5 8630
deb33d369d2d2c516894000057b68ab5 8647
deb33d369d2d2c516894000057b68ab5 9105
deb33d369d2d2c516894000057b68ab5 9106
deb33d369d2d2c516894000057b68ab5 9107
deb33d369d2d2c516894000057b68ab5 72814
--8<---------------cut here---------------end--------------->8---

If there is something I can help to debug this, let me know, or if this seems
like a bug to you as well, I can submit a bug report.

References:
[1]  http://git.savannah.gnu.org/cgit/emacs.git/tree/?id=49a42fb

Thanks!
-- 
Ashish SHUKLA

“Private misfortunes must never induce us to neglect public affairs.”
             ("Alexandre Dumas", "The Count of Monte Cristo", 1845-1846)

Sent from my Emacs