Click Web and Email → Web access protection and expand URL Address Management. Click Edit next to Address list.
Figure 1-1
Select List of blocked addresses and click Edit.
Figure 1-2
Click Add, type the web addresses of the sites that you want to block and then click OK. Click OK in open windows to close them and exit Advanced setup.
Figure 1-3
Wildcards and other recommendations
The wildcards * and ? may be used. For example, if you wanted to block all addresses from nk01.sample.com to nk98.sample.net, you would enter: nk??.sample.*