UNSEEN flag issues with multiple clients

[John Stoffel]

>>>>> "John" == John Stoffel via dovecot <dovecot at dovecot.org> writes:

>>>>> "Sami" == Sami Ketola via dovecot <dovecot at dovecot.org> writes:
>>> On 1 Oct 2019, at 21.45, John Stoffel via dovecot <dovecot at dovecot.org> wrote:
>>> 
>>> 
>>> Hi all,
>>> 
>>> I've been bugged by this issue for a while, and while I see that the
>>> \UNSEEN flag is specified in the RFC to be reset once *any* client
>>> connects and looks at a mailbox, I was wondering if there's a way to
>>> change the behavior so that it's tracked on a per-client basis?
>>> 
>>> Or if there's even some way to turn it off so that both my iPhone mail
>>> client and my main emacs viewmail mail client don't stomp over each
>>> other when looking at my mail folder counts of unread messages.
>>> 
>>> My mail server is running Debian 9.11, which has dovecot
>>> 2.2.27-3+deb9u5 as the version.  I'm only running IMAP, no POP at
>>> all.


Sami> A SELECT INBOX updates \Seen flags, A EXAMINE INBOX does not.

Sami> there is no configurable value to change the behaviour. Maybe
Sami> you can change your client to use EXAMINE instead of SELECT.

John> I kinda figured it wasn't an easy issue to address.  Since one of my
John> clients is an iPhone, I doubt I can fix that client.  :-)

John> But hmm... maybe it's not the iPhone causing problems, but my emacs
John> based mail client viewmail, and that I have the source for.  Thanks
John> for the hint, I'll see if I can chase this down more.

So looking at the traces of my client, I see that it's doing (slightly
edited) sets of commands:

    VM OK Logged in

    VM LIST "" "*"

    * LIST (\HasNoChildren) "." postfix-users

    .
    .
    .
    * LIST (\HasNoChildren) "." INBOX

    VM OK List completed (0.000 + 0.000 secs).

    VM STATUS "INBOX" (MESSAGES RECENT)

    * STATUS INBOX (MESSAGES 1013 RECENT 0)

    .
    .
    .
    VM STATUS "postfix-users" (MESSAGES RECENT)

    * STATUS postfix-users (MESSAGES 1588 RECENT 6)

    VM OK Status completed (0.000 + 0.000 secs).

    VM LOGOUT



To look at all the mailboxes on the server and see how many RECENT
mails there are.  For the postfix-users list, I see that there are 6
recent messages.  And if I do the list of mailboxes command again, it
returns the same count.  Then if I go and look at the postfix-users
folder with my iphone, I see that I have 11 unseen messages.  And
without opening a single message, I went back to my other MUA and
listed the folders, and now I have 0 unseen messages for 'postfix-users'

I'll have to see if I can log the commands sent by my iPhone from the
server side to see what's going on here.  But as you can see, it's an
annoying behavior.

Thanks,
John