MBOX-Line: From imap at maclean.com  Mon Nov  7 10:09:20 2011
To: imap-protocol@u.washington.edu
From: Pete Maclean <imap@maclean.com>
Date: Fri Jun  8 12:34:47 2018
Subject: [Imap-protocol] [noob] select & unseen?
Message-ID: <mailman.5.1528486487.22076.imap-protocol@mailman13.u.washington.edu>

At 11:52 AM 11/7/2011, Mark Crispin wrote:
>On Mon, 7 Nov 2011, Bron Gondwana wrote:
>>RFC 3501 says      " If this is missing, the
>>                     client can not make any assumptions about the first
>>                     unseen message in the mailbox, and needs to issue a
>>                     SEARCH command if it wants to find it. "
>>That means there is NO WAY for the server to communicate "there are no
>>unseen messages in this mailbox" in an unambiguous way.
>
>That means that if a client expects to know the position of the first
>unseen message at select time, instead of doing a SEARCH, it can not
>discriminate between the case of "there are no unseen messages" and
>"server does not support sending that information."

This is proving to be an interesting discussion for me because I have 
a customer with a special sub-case of "there are no unseen 
messages".  Which is that they never have any unseen 
messages.  (Their message store is an archive.  I don't know whether 
they don't archive unseen messages or simply don't support a SEEN 
flag.  But that's not my business.)  They expressed concern that 
there is no way to indicate in a SELECT response that there are no 
unseen messages.  This might seem to necessitate an always 
superfluous extra command-response for a client that insists on 
knowing about unseen messages.  However, if I understood one of 
Mark's comments correctly, it seems likely that many clients will not 
care about this information in isolation but only message flags in general.

I did suggest to this customer that an unsolicited STATUS response 
could be sent of the form:

* STATUS Mailbox (Unseen 0)

but also expressed serious doubt that any client would pay 
appropriate attention to this.

Does anyone else have any wise words to offer about this situation?

Pete Maclean  


