On 10/28/06, Oded Arbel <[EMAIL PROTECTED]> wrote:
On Wed, 2006-10-25 at 01:33 +0200, Michael Vasiliev wrote:
> On Monday October 23 2006 20:28, Gil Freund wrote:
> > Hi,
> >
> > I am using a Amavis+SA+CLAM for mail filtering (debian sarge packages).
> > Recently I am being hit by a lot of image spam. Bayesian filtering and
> > RBL's are not enough.
>
> These mails are terrible, while my personal accounts get a few dozen each,
> Linux-IL posting address gets a hundred per day minimum. If we only relied on
> SA's checking, this list would look much worse than LKML. Most of these
> emails are a crazy mix of sentences on random topics, probably web-crawler
> generated, plus a gif image with a nasty ad of some kind (I never care enough
> to mimedecode them).
The problem is that the image has some random noise added to it, so you
can't even get your bayesian filter to recognize the mime data. This
will also, IMO, in the long run defeat OCRs in the same way that
CAPTCHAs defeat OCRs.
> SA's Bayesian filtering is terrible, I don't know why. (All right, I admit I
> am too lazy and illiterate at adult-level mathematics to figure out why). I'm
> running SA and bogofilter in parallel, clearly bogofilter is at least twenty
> times more accurate.
I'm using bogofilter in conjunction with a large set of RBLs, and while
I do see a surge in the number of small-caps and viagra image spam, only
rarely there is a false negative - about 4-5 times a week.
--
Oded
::..
If you lost your left arm, your right arm would be left.
This could be off topic...
but I have unorthodox way to filter spam...
I auto forward my emails to a gmail account that i opened for this purpose only.
then from the gmail account i Auto forward the email back to other secret email for viewing the emails.
Gmail have a very strong spam filters and the spam will not be auto forwarded to you.
My old personal email was heavily spamed in a way that I gave up on that email, since i got hundreds of spams everyday but now I get only the real emails.
This might be a good and fast solution for personal emails and private machines, I am not sure if it will work for a mail server that serve lot of people, though it might be possible with some tweaks to the DNS and mail server.
forgive me for suggesting this (no offense) but you can also put your email domain under google apps
Michel
