In general, I agree with Charlie's comment, but in this particular case I know the answer & it's to do with some of the updates you've applied.
You'll need to downgrade to the following packages (they should be on the SME 6.0.1 CD):
e-smith-email-4.14.0-07.noarch.rpm
e-smith-lib-1.14.0-10.noarch.rpm
That will allow the spamfilter panel to work.