If you would like to be notified when someone replies to your post, you can do so by clicking the little flag tab under the text window of your post.

It is also possible to be notified every time another registered member writes a new post (many on this board are fans of Chris Vaughan's helpful advice, for example). To do so, Click the person's name within the interface, then select "notify me of new posts by x". You will be notified via email every time that member posts to the community.