Bayesian
Spam Filters Explained
by: Niall Roche
In a word Bayesian spam filters are "intelligent".
Bayesian spam filters are intelligent in so far as
they're capable of comparing two sets of information
and acting on the result. This is in direct contrast
to the vast majority of other spam filters who use
pre-built rules to decide which e-mail is spam and
which is not.
Bayesian spam filters can take one group of legitimate
e-mail and another group of spam and compare the values
and data of each. The definition of legitimate e-mail
that it creates at the end of this comparison session
is what it uses going forward to scan your inbox for
spam.
FYI Bayesian spam filters are named after Thomas Bayes
an 18 century cleric who created something known as
Bayes Theorem. In summary Bayes Theorem is as follows:
.."in statistical inference to update estimates
of the probability that different hypotheses are true,
based on observations and a knowledge of how likely
those observations are, given each hypothesis."
In plain English it looks for obvious repeating patterns
to form an "opinion" on something. In spam
filter terms that "opinion" becomes a rule
which keeps you spam free (or pretty close :-)
The really neat thing about Bayesian filters is that
they're capable of learning. For example if they decided
to block an e-mail because the filter perceived it
as junk but the user marked it as valid mail the Bayesian
filter then knows not to block that type of e-mail
in the future. So, in time, this type of spam filter
learns enough to block spam far more effectively.
AOL have embraced this type of spam filter with the
launch of AOL 9.0 and AOL Communicator- if the big
dog wants it then it must be worthwhile?
So what Bayesian spam filtering options are available
to you? Well quite a few to be honest and you'll be
pleasantly surprised by some of the names involved
:-) The first one on the list is AOL with their AOL
Communicator product. The spam filtering features
in AOL Communicator and AOL 9 are, to be honest, impressive.
Think what you will of the provider themselves AOL
Communicator is an excellent product and is suitable
for use by both PC and Mac OSX users.
Next up we have Eudora. The nice folks at Qualcomm
have designed an excellent e-mail client that also
has built in Bayesian spam filtering. I've used Eudora
in the past and it's a neat little package. Again
the benefits here are advanced integrated spam filtering
with your e-mail automatically. Mac OSX and OS9 users
are in luck with Eudora providing support for both.
If you'd like to know more about spam filters or just
spam in general please drop by our site at www.spam-site.com
About
The Author
Niall Roche is the content author and owner of http://www.spam-site.com.
niall@spam-site.com
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