How can I acces internet w/IIS?

Our email server here at work does not allow you to browse the internet. Is there a setting that needs to be turned on to accomplish this? I did not set up the server and really don’t have too much experience setting up email servers. The server is running Windows 2003 Server and running the ArgoSoft Email client. We believe we may have a virus on the server, but Norton AV is not finding anything. I’ve used the Trend Micro free online PC scan that has found viruses, worms, etc. that Norton AV could not find. I would like to run this on this server but cannot access the web. Can anyone let me know how to turn this on and then back off? Thanks.