Thought I'd dig this out of the Community 'Help' bit:
"Subscriptions let you get email updates whenever new content appears in an area of the community that you're interested in. You can subscribe to a board, a blog article, an idea exchange, or any other location in the Community. You can also subscribe to a specific post.
To subscribe a piece of content:
- Go to the item you want to subscribe to.
- To subscribe to a location, click (Location) Options > Subscribe.
To subscribe to a specific post, go to the post and click (Post) Options > Subscribe
To view and manage your subscriptions:
- Go to My Settings > Subscriptions & Notifications.
- Click My Subscriptions to see a list of the items you've subscribed to.
You can click a subscription to go to the item.
- To delete a subscription, click the check box for the subscription and click Email Subscription Options > Delete Selected Subscriptions."