[vox-tech] spam current events

Micah J. Cowan micah at cowan.name
Thu Aug 31 15:02:14 PDT 2006


On Thu, Aug 31, 2006 at 02:47:30PM -0700, Rod Roark wrote:
> On Thursday 31 August 2006 13:51, Peter Jay Salzman wrote:
> > i'm getting hammered with email containing text designed to trick bayesian
> > filters....
> 
> I think content filtering is almost a waste of time.  As you see, 
> spammers can always design content that gets past the filters.  What
> else are you doing to combat spam?
> 
> The blacklists (RBLs) are my core defense, however some stuff
> inevitably gets through.

More disturbingly, good things inevitably get blocked. Some people's
experience have shown that too many RBLs let politics interfere with
their jobs, and block sites for questionable reasons. I'm not speaking
from my own experience on this, so please don't ask me to corroborate
this claim ;-)

Spamhause's SBL has been one of the more reliable services, in my own
experience and that of others from whom I've heard.

But, Rod, while content filtering is a continual game of one-upmanship,
it /is/ fairly effective when it's kept up-to-date. And, of necessity,
RBLs will always have some degree of lag.

One relatively effective method is to combine content-filtering with
RBLs (intent-checking: SpamAssassin will do this with spamhaus if you
enable it). But spammers still have some sneaky tricks in dealing with
this, so the engine you use to reap URLs from an email needs to be
effective; and you need to have fast lookups maybe combined with
whitelists, because spammers will throw in 50 good URLs to confuse the
scanner, or tie it up with too many lookups. I can't comment on the
effectiveness of SpamAssassin's engine; Barracuda Networks uses the
engine I wrote.

-- 
My $0.02,

Micah J. Cowan
Programmer, musician, typesetting enthusiast, gamer...
http://micah.cowan.name/


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