Recently Facebook has changed their default email notifications settings, so that most people will be getting fewer emails from Facebook. To view or change your email notification settings, visit Account / Account Settings, and click on Notifications in the left-hand menu. The new setting is called Email Frequency, and the default setting is now checked. When checked, you will only receive summary emails and those notifications Facebook deems as important. You can modify which individual actions result in an email being sent by scrolling down to “All Notifications” and editing the settings under Facebook, Photos, Groups, etc.
Click on thumbnail to view screenshot in full size: