If you haven't already done so, I would check your 'Messaging and Notification' before I emailed admin.
First go to 'User CP' at the top of this page, then go to "Edit Options' on the left hand side of that page. Then look at 'Messaging & Notification' and change the 'Default Thread Subscription Mode' to receive email notification to either instant, daily or weekly.
If I've gotten any of this wrong, I trust that a Mod will be along shortly to correct me.