How to enable private messages notifications for vBulletin users?
You can allow all vBulletin forum members to receive private messages by running a query under the vBulletin admin area > Maintenance > Execute SQL Query. Pick the Yes – Receive Private Messages option from the Automatic Query drop-down menu. Then run the query by clicking on Continue.
If you want to enable the notification e-mails when private messages are received navigate to the same area (vBulletin admin area > Maintenance > Execute SQL Query) and pick the Yes – Send Notification Email When a Private Message is Received option. Again, click on Continue to execute it.
The third option associated with private messages is related to the notification box that can pop-up when a private message is received. To enable it, pick the Yes – Pop up a Notification Box When a Private Message is Received option.