Re: [Evolution] How does expression work in a filter?

[Not Zed <notzed ximian com>]

On Thu, 2004-03-18 at 08:34 +0100, Bram Mertens wrote:

> On Wed, 2004-03-17 at 17:58, Rick DeNatale wrote:
> [...]
> > I'd like to be able to filter on some of the SpamAssassin tags, for
> > example, I'd like to make a vfolder which shows any e-mails which have
> > RCVD_IN_* in the X-Spam-Status header to get an idea of which blacklists
> > being considered by SA are generating false positive indications.  Is
> > this something which can be done, either in 1.4 or in 1.5?
>
> I believe you'll have to write a little script that looks for the
> headers and returns 1 or 0 when they're (not) found.  Then you can use a
> filter to pipe the messages through this script and assign a
> label/score/whatever to the message and use that as a rule for the
> vfolder.

You don't have to do this using a command, you can just do it using the
filters.  Filters can do regex and other stuff on arbitrary headers, or
even the entire message content - vfolders and searches are more limited
in what they can do directly.

You could for example setup a filter that either just uses a substring
expression or regex to match the header (you can do this in filters but
not in vfolders), and then use that to set a score on the message (i
don't know why you can't assign a label ...).

Then have a vfolder (or just a search) which runs against the score.

(i dont know why i didn't think of this earlier).

> It's a little bit complicated and might be quite slow though, I have no
> idea how much load this would cause...

The above should be fairly fast (essentially free if you already do any
filtering).