Change scoring?

[Juan Mas]

Im looking to change scoring in my SA setup.  As it stands now, we know mostly what e-mails and from who we will be receiving to our system that SA is monitoring.  Id like to make our scoring a bit more strict.  Right now Ive got spam being flagged at required score 1, and I still have a good 20% coming through the system.  Can anyone point me to where I can go about changing the rules scoring?

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-Juan