posting via e-mail

I am a WP newbie and am working with Wp 2.0 trying to post by e-mail. I set up a POP3 account with a secret email address that I entered in on the post form but… email I send to that address doesn’t post.
Am I missing something besides that form I filled in, a plug-in I need to install and activate, a place to set how often WP looks for email at the secret address, or something I’m too dumb to even know how to ask about?