Re: [Evolution] Applying filters automatically.

[Patrick O'Callaghan <poc usb ve>]

On Sat, 2008-02-02 at 15:37 +0000, Gavin Simpson wrote:
> On Sat, 2008-02-02 at 12:40 +0000, Pete Biggs wrote:
> > On Fri, 2008-02-01 at 17:19 -0700, Steve Karmesin wrote:
> > > On Feb 1, 2008 5:08 PM, Pete Biggs <pete biggs org uk> wrote:
> > >         
> > >         BUT - I do think it needs to be sorted out - I regularly
> > >         answer this
> > >         same question on the list and it is clearly not intuitive to
> > >         people.  It
> > >         may be an issue with particular IMAP clients or particular
> > >         combinations
> > >         of setups, but it does need to be documented.
> > >
> > > I just want to reiterate:  this isn't just not intuitive, it is not
> > > nearly as useful to many users.  Why not have the mode that mimics
> > > what t-bird does as an option?
> > But what *does* Thunderbird do?  A few people have said that it's better
> > at doing it, but no one has actually enumerated the logic that it goes
> > through.  i.e. does it only filter 'unread' or unseen to that particular
> > client instance or does it mark a message as having been filtered?
>
> Lets see if I can give a non-programmer's view of what tbird does ( I
> just installed it on my Fedora box to try with my University IMAP
> account).
>
> Tbird was set to check for new messages once every 10 minutes. I created
> a single message filter to match messages from another email list I am
> on. This filter was set to move any messages from this mailing list to a
> different folder on the IMAP server.
>
> When the 10 minutes were up tbird checked for new messages, notified me
> that new messages were downloaded, and then went through each new
> message that was downloaded and checked it against the filter. The two
> new messages that were from the mailing list were marked as read and
> marked deleted in the INBOX, the message was moved to the correct
> folder, where it was marked as Unread. The new messages not matching a
> filter, remained marked as unread in the INBOX.
>
> Tbird only filters new messages automatically - the ones it just
> downloaded, not others in my inbox.
>
> This is what Evo does not do. All messages are left in the INBOX
> regardless of filters when new messages arrive in my INBOX. So tbird
> does what I want and Evo doesn't in this regard.

I think it might be helpful to enumerate the various flags that messages
can have, so we can define exactly what we would like Evo to do. This is
a first attempt; please correct it if necessary:

Unseen: this is an IMAP server state which only the server can
manipulate. Messages which have never been opened by any client are
marked Unseen, otherwise they're not.

New: the IMAP client marks as New those messages which *it* hasn't seen
before. Thus the client can set/unset this flag as it likes, but the
state is not reflected on the server so other clients will not be aware
of it. (I may be wrong about this).

Read: the IMAP client marks messages which it has shown to the user as
being Read, but this is highly configuration and client-dependant. Most
clients set the Read state after a configurable number of seconds. Some
allow you to turn this off completely (Evo does, TB doesn't). In any
case, this state *is* reflected on the server so other clients can see
it, depending on when a server sync is done. (I may also be wrong about
this).

I suspect that the difference between Evo and most other clients is that
Evo only filters messages marked Unseen, while other clients filter
those they consider New and ignore the Unseen state. Note that
Unseen=>New=>!Read but that's about the only guaranteed relation between
the flags and I'm not even sure about New=>!Read for all clients.

poc