Make sure im doing this right

[Matt Kaminer]

Our Mailscanner / SpamAssassin / Bayes / Big Evil List / ChickenPox /
SpamCop.Net setup has been doing so well I have never gotten a false
positve (although I get false negatives every so often).

We have the Spam score set to 6 and high scoring spam set to 10.  We
deliver spam and delete high scoring spam.

Ive been thinking about lowering the high scoring spam to 8 and lowering
spam to 5.  Lowering the spam level to 5 would basically wipe out all my
false negatives.

My question is this:  What is the "normal" settings.  Is 5 and 8 for high
scoring spam too low?

Thanks,
Matt