MBOX-Line: From janssen at parc.com  Sun Mar 11 13:23:23 2007
To: imap-protocol@u.washington.edu
From: Bill Janssen <janssen@parc.com>
Date: Fri Jun  8 12:34:38 2018
Subject: [Imap-protocol] message sequence numbers vs. message UIDs
In-Reply-To: <07Mar8.112542pst."57996"@synergy1.parc.xerox.com> 
References: <07Mar8.112542pst."57996"@synergy1.parc.xerox.com>
Message-ID: <07Mar11.122327pst."57996"@synergy1.parc.xerox.com>

> In this system, the mailbox message sequence numbers are the same as
> the message UID numbers, so that's why you're seeing the same value in
> both places.  By the way, are there pitfalls with that design I'm not
> seeing?

I think I've answered this myself.  Yes, it's impossible to use the
same value for both, as message sequence numbers must reflect the
exact number of messages currently in a mailbox, while UIDs must be
continuously increasing.  The message sequence number is simply the
current one-based index of the message in the mailbox.

Bill

