This is how to check where you set the parameter.
1. At the very top of any page on this site, there's a black background box that says Welcome (username), Inbox, My Profile, Settings, Log Out. Click on Settings.
2. On the left side of the page, you'll see a big box labeled My Settings with a lot of options. Under My Account, click on General Settings.
3. In the settings on that page, under Private Messaging, you should see this option with two choices:
Email Notification of New Private Messages:
- Receive Email Notification of new Private Messages
- Don't receive Email Notification of new Private Messages
If it's not set to receive e-mail notification, click on that and then on Save Changes at the bottom.