[Dovecot] Hooks on folder operations

[Grahame Bowland]

On Wed, 2003-07-23 at 23:17, Timo Sirainen wrote:
> On Wed, 2003-07-23 at 17:50, Maikel Verheijen wrote:
> > > I'm interested in implementing an anti-spam system using 
> > > bayesian filtering. I had the idea of modifying and IMAP 
> > > server to assist in training the spam filter.
> > Why do you want to hook it up into your imap server? I think it would
> > be better to prevent emails to enter the mailbox with the MTA rather
> > than removing it when the user is reading his email using imap.
> > 
> > Why? Because the spam that is in the mailbox might push the user over
> > his quota limit, and thus preventing legitimate emails to be
> > delivered.
> 
> Well, I'd actually want that too. I don't have quota problems and I make
> spamassassin put all spam into spam mailbox. The few spams that go
> through to inbox I usually just delete because I'm too lazy to make
> spamassassin's bayesian filter to learn it. If I only had to move them
> to spam mailbox, I'd probably do it :)
> 
> > With the new API code that Timo is making now, I guess this would be
> > possible.
> 
> Yep.

Ah, cool.

The idea (I don't think I was clear enough) is to allow the user to move
their spam into the "spam" folder manually. This is for spam that gets
through the filter. When the mail is moved, a program runs (at the
instigation of the IMAP server) that parses the spam email and updates
the statistical information used to detect spam.

Actual detection of spam is done in the local delivery agent, rather
than in the IMAP server :-) We do tend to store mail we think is spam so
the users can check, as most spam detection systems get a lot of false
positives.

> > You can always build a plugin, and plugins can be loaded whenever an
> > administrator wants them to load. I don't know if Timo wants to
> > include all plugins that are / will be written for dovecot, but I
> > guess there might be a plugins part, where people can "post" their
> > plugins so other people can benefit from them :)
> 
> I'll probably just add a plugins web page. Some of the most useful ones
> I'll include in the tarball. Also I'll make it possible to compile the
> plugins into the main binary so there's no overhead in dynamically
> loading them.
> 
> At least quota and ACLs are going to be plugins. I'll make sure my APIs
> are flexible enough to allow that.

Great - I'll look at this at work in the morning. Thanks for the idea,
I'll look at implementing this as a plug-in.

By the way, thanks for your work on Dovecot. I'm looking at moving quite
a few systems over to it from UW-IMAPd. It's really very good :-)

-- 
Grahame Bowland                       Email: grahame at ucs.uwa.edu.au
University Communications Services    Phone: +61 8 9380 1175
The University of Western Australia     Fax: +61 8 9380 1109
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