Re: [Evolution] Applying filters automatically.

[Paul Smith <psmith gnu org>]

On Fri, 2008-02-01 at 14:23 -0700, Steve Karmesin wrote:
> I would vote for A.  Just doing B would mean that I can quickly find
> out that I don't want to use Evolution, which is an improvement over
> the current situation, but I need A for Evolution to be useful to me.

Although I'm sure the Evo developers would like Evo to be used by
everyone, it may be an acceptable price to be paid for having Evo do
what the developers feel is correct.  With free software, sometimes
doing the right thing is more important.

The problem is, we can't judge whether this is one of those times or not
because we don't fully understand the current situation OR the
alternatives.  So that's where we need to start.

> Thunderbird does the expected thing and without a performance impact.
> I strongly suspect that it just uses different logic than relying on
> the server to tell it if the mail is "new".  If you're downloading a
> message for the first time and it is unread, then apply the filters.
> Or something very similar to that.

Exactly.  The first step is documenting what is done today.  The next
step is figuring out how other mail clients REALLY work, under the hood,
and not just guessing.  Only then can we determine whether there are
downsides to those methods that are sufficiently egregious to make the
enhanced functionality not worthwhile (or perhaps make it optional).

Thomas Novin <thnov xyz pp se> writes:
> ïCan't Evolution just filter messages that is new to Evolution (not
> caring about the status on the IMAP serer or other server).

It's not that easy.

The thing is, we're talking about IMAP here.  The whole point of IMAP is
that all your mail is left on the server!  It's not downloaded to the
local system at all: the mail doesn't exist there.  So when you connect
to the server, how do you know that you haven't read that message
before?  That's the question.

The answer according to IMAP is to check the "new" flag that the server
is supposed to maintain for you.  You can ask the IMAP server to send
you ONLY the messages marked as "new".  Very fast, very easy.

If you can't trust that, then the only alternative is to keep some kind
of local cache on the client side that "remembers" what messages on the
server have already been read.  But then when you connect, you have to
ask the server for ALL the messages (or at least the headers) so you can
figure out which ones you have already got in your local cache and which
you haven't.

As Pete mentioned, if you have 50 or even 500 messages in your folder
that's one thing.  But if you have 5000 or 10000 messages in your
folder, that's quite another thing!

And we haven't even touched on the issue of multiple clients for the
same server/account (say you read your mail from home and also from
work), or what happens if your local cache is lost or corrupted.

-- 
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 Paul D. Smith <psmith gnu org>                 http://make.mad-scientist.us
 "Please remain calm--I may be mad, but I am a professional."--Mad Scientist