Email notification options are configurable in your forum settings. To go to your settings, click your user icon in the top right corner of this page, then in the menu choose "My Settings."
Also when you post a question, there is a place to checkmark "Email me when someone replies." It's not real prominent, however, and can be easily missed. I believe it's just to the right of the question body. I believe it is already checkmarked by default.
