scheduled emails via Calendar app

I tried to send a scheduled email from the calendar (iCal) by creating an .app file with Automator and linking it to an event via the custom feature in the alert option for a calendar event. However the email does not get sent. The calendar app does not even safe the custom alert option - when I open the event after setting it all up and closing the iCal then the alert (the send the email request) has disappeared.

Any similar experiences?