I read about rss support. How do you use this? I have gravity and Forte Agent, are these suitable clients?

If not, what do I need. Is anything open source?
I started to receive complete messages via RSS (my mail client is Outlook Express). I think it is when I subscribed to each "watch forum" that I stopped getting actual messages, only notifications that a message was posted. My confusion is now total. What do I need to do to receive all posts (not just subject lines or even less, notification that someone posted, but the whole message bodies) via my mail client?