There are two things that must happen before a user will see the Manage Notifications options.
1. The user needs to have the Space Developer role assigned to the space where a notifying application is running.
2. The application must have sent at least one notification to the notifications application for a user.
One way to test this is working is by creating an autoscaler service and bind it to an application in a space where a user has the Space Developer role.
a. Drill into the application and set the autoscaler instance limits to min 1 and max 5.
b. Then create an autoscaler rule for Container Memory low 1% and high 2%. This will cause the application to breach the threshold, scale and trigger a notification with autoscaler, which will get sent to the the notifications app.
c. Once this happens you will notice that the e-mail options for the user will appear on the preferences page.
Note: When using autoscaler to test this, setting min and max to scale the app is not enough. You must setup a rule.