Setting up RSS in the Mail Program

I'm now a little familiar with RSS, and so I want to take advantage of it in my Mail program. But I think when I initially set up the Mail program, I deleted the RSS folder. When I click on Mailbox, Get New Mail, I see the RSS link, but it is dimmed so I can't select it. How do I get it back? Or how can I set up RSS in my Mail program? Thanks. David