Advertising is a wonderful thing and, in the best snake-oil tradition, Semantec will claim many things to promote their products. I don't know what the law is in your part of the world but, if you can get your money back for goods unused, my advice would be to do just that.
If you want to use something sensible, for example to block pop-up ads while you're surfing and to manage those annoying cookies, switch to
http://www.Mozilla.org right now rather than continue with Explorer or the unmodified Netscape. There are also some good e-mail scan packages out there, but whether you can install them will depend on your general skills and knowledge around Macs.
Mustn't ramble on.
Good luck
David