Associate email with shell account?

I just created a new shell account, so I can run a procmail-based agent on it. How can I associate this shell account with an email address sent to my domain, so that when mail is sent to that email address, it can be processed by my .procmailrc?

Scroll down this blog entry to below the computer falling out of the window:
http://blog.dreamhost.com/2008/05/23/what-web-hosting-is-for/

-Scott