SpamAssassin rule for stock pump and dump spam

[blu at vl.com (Tom Metro)]

Nicholas Bodley wrote:
> Tom Metro wrote:
>> [...] it still seems like there should be an automated service for 
>> updating the rules periodically.
> 
> Opera e-mail has a "trainable" spam filter, but Opera being closed 
> source, it's not obvious how that filter works.

Probably a Bayesian statistical filter or similar. There are plenty of 
open source implementations of these, including one in the Thunderbird 
mail client.

These filters work by developing a database of statistics on the actual 
good and bad email you receive. Because they are trained using your 
actual mail, there's no need to download or update filter rules.

However the type of rules Rich was posting about were hand crafted 
rules, which do need to be periodically updated as the spammers adjust 
their tactics.

I believe SpamAssassin now either incorporates a statistical filter or 
interfaces to them, but its primary attraction are the hand crafted 
rules. Each approach has some pros and cons.

  -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/

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