Hello,
I have noticed a similiar thing, as well as poor bayesian guessing as well. I am not sure which rule needs to be changed (or removed) but here is where the spamassassin configuration is stored.
The templates are in /etc/e-smith/templates-custom/etc/mail/spamassassin
once you expand the template check it against /etc/e-smith/etc/mail/spamassassin
let me know what you find out, I am sure the SA project website would be helpful too.