Re: [Evolution-hackers] SA rules adjustment

[guenther <guenther rudersport de>]

On Thu, 2004-01-29 at 17:53, Radek Doulík wrote:
> On Wed, 2004-01-28 at 22:24 +0100, guenther wrote:
> > > > 2) Excluding the Habeas headers from Bayes would be good too. Otherwise,
> > > > getting more SPAM as HAM with this faked headers will poison the Bayes
> > > > database and HAM will get bad Bayes scores.
> > > 
> > > I am not sure about this. It may cause trouble in case the bayes db is
> > > already poisoned. Otherwise it should work OK.
> > 
> > I'm not sure, if I understand you.
> > 
> > Excluding this headers means, their existence and the values will
> > neither be a sign for SPAM nor HAM. Which this headers definitely are
> > ATM, being abused by SPAMmers.
> 
> yeah, so it's pretty good sign of spam right now and bayes filter will
> profit from it.

I wouldn't say this is sign of spam. Should be considered as neutral in
the worst case.

<sarcasm> If you really think, this is sign of spam, then why adjusting
the score to 0 instead of a positive value? </sarcasm>

The hackers and users on the SA mailing list agreed, this must be set to
a value <=0. Probably most of them adjusted to 0, some uses nagative
values like -1. It was strongly advised to *not* use a positive value,
as this must not be a sign for spam.


> when it eventually become HAMs again, the filter will
> learn that from user (or from us when we turn HABEAS score on again) and
> this header will be neutral in bayes db.

No. It will be punished with a bad Bayes score until the user got at
least as much HAM with the Habeas headers as he already got as SPAM.

Even worse: Those mails will *NOT* be auto-learned as HAM, as they have
a bad Bayes score.


However, I will have to check if those faked Habeas headers are still
used in the wild.

...guenther


-- 
char *t="\10pse\0r\0dtu\0  ghno\x4e\xc8\x79\xf4\xab\x51\x8a\x10\xf4\xf4\xc4";
main(){ char h,m=h=*t++,*x=t+2*h,c,i,l=*x,s=0; for (i=0;i<l;i++){ i%8? c<<=1:
(c=*++x); c&128 && (s+=h); if (!(h>>=1)||!t[s+h]){ putchar(t[s]);h=m;s=0; }}}