Re: [Evolution] Wish: Uncached IMAP folders

[Patrick O'Callaghan <poc usb ve>]

On Wed, 2006-04-26 at 18:41 +0100, David Woodhouse wrote:
> On Wed, 2006-04-26 at 07:32 -0400, Patrick O'Callaghan wrote:
> > On Wed, 2006-04-26 at 01:09 +0100, David Woodhouse wrote:
> > > On Mon, 2006-04-24 at 22:52 -0400, Patrick O'Callaghan wrote:
> > > > I'm speechless. Was this done because some IMAP servers were buggy? If
> > > > not, there would seem to be no justification for it.
> > >
> > > I believe it was done in order to fix inconsistencies in the unseen
> > > counts on folders when the strange client-side Junk processing isn't
> > > disabled. The Junk processing hides messages from a folder and pretends
> > > that those messages actually exist in some other fake folder. And thus
> > > the unseen counts in the real folder looked wrong, because some of the
> > > unseen messages were hidden from view. 
> >
> > I see.
> >
> > <sarcasm>
> > So even when I don't have Junk processing enabled, the rest of Evo Mail
> > is slower and causes extra load on the network *and* the server.
> > Brilliant!
> > </sarcasm>
>
> Don't forget your local disk -- you cache the headers of every mail in
> every folder of the mail server. If you were to delete them from your
> local cache, Evolution would refetch them when it checks for new mail.

Even better!

> > > The simple option might have been to mark the messages as read when we
> > > decided they were junk.
> >
> > That would work. Currently, when the user explicitly marks something as
> > Junk, it also gets marked as read (even if he hasn't read it).
>
> It _doesn't_ get marked as read on the server.

But it does get marked in the client. In other words, the client is
lying (see below).

>  That's why we can't just 
> ask the server how many unread messages there are -- because its idea of
> what's unread (and indeed of which folders exist and which mail is in
> which folder) isn't coherent with what we're displaying to the user.

This incoherence is all over the place, expecially when you consider
multiple clients. The only way to deal with it sensibly IMHO is to have
an explicit Synch button. That way the user isn't deceived into thinking
he's in synch when he isn't, and can be made aware that it's a
potentially expensive operation. You can kind of get the effect by
switching folders, but most users don't know that and in any case
there's no committment for it to stay that way in future versions.

poc