MBOX-Line: From brong at fastmail.fm  Mon Jun  6 14:42:38 2011
To: imap-protocol@u.washington.edu
From: Bron Gondwana <brong@fastmail.fm>
Date: Fri Jun  8 12:34:46 2018
Subject: [Imap-protocol] Where to start?
In-Reply-To: <4DED435D.9070900@psaux.com>
References: <4DEBB242.2090200@BusCom.net> <4DEBB58D.3090101@logicprobe.org>
	<4DEBBAB3.2030301@BusCom.net> <4DEBBEC1.3080600@BusCom.net>
	<201106051924.p55JOwpG003543@mxout12.cac.washington.edu>
	<4DEBDFF5.9000301@BusCom.net> <4DED435D.9070900@psaux.com>
Message-ID: <20110606214238.GA13095@brong.net>

On Mon, Jun 06, 2011 at 02:15:09PM -0700, Tim Showalter wrote:
> On 6/5/11 12:58 PM, Lynn W. Taylor wrote:
> >The mailstore is in RFC-2822 format. There is a UID, and it's cast in
> >jello -- it can be changed so that the POP3 server uses an IMAP
> >compatible UIDL. I think I can keep the UIDs unique and ascending as
> >required in the RFC.
> 
> Ancient versions of Cyrus used only the UID as a UIDL value, and it
> can cause problems when a user is moved from one POP server to a new
> host. POP has no equivalent to UIDVALIDITY, and the only way to blow
> the cache is to change all the UIDL values.
> 
> If you use the UIDVALIDITY+UID as a UIDL scheme, that works pretty well.

We're still suffering for that.  Every new folder and every folder
that ever gets down to "EXISTS 0" gets the new scheme, but "old"
folders still do it.  Just in case someone has upgraded from
ancient Cyrus and they don't want to POP everything again.

Bron ( gotta love backwards compatibility.  Still, it costs
       about 8 lines of code total, and one bit in a not very
       full bitfield )

