e_filed, setAlert, Route Data

When we use setAlert in the API to register for e_filed notifications, is an alert sent when the original flight plan is filed, when ATC provides official clearance for the route or both?

For example, a user files a flight plan with one route.
ATC then reviews and changes the route, providing clearance for the new route, but not the original filed route.

How many alerts would be received?

Thanks!