directory harvest attack recognition feature

Hi,

I have been going through this blog ( https://www-secure.symantec.com/connect/blogs/typo... )  and could not figure out how to configure  directory harvest attack recognition feature.Is it something we need to set in the Symantec Server or the SPAM filter ?

Here is the brief one liner :

Symantec advises users to configure directory harvest attack recognition to protect their website environment, and to update their spam filter algorithms to repel such attacks.

Could you please guide me how to configure this ?