I know that there is a complex internal functionality for sending emails from an ERPLN program. I had tested the functionality a long time ago and it did work!
Programmers can find the information hier: Emessage Connector Overview
To Maria: I don't know if there is another more user freindly way to send emails but the Emessage Connector
method mentioned above needs a real expirienced programmer to write a program to register the status change of orders -say per user exit as mentioned per serkan- and then create another program to create and send the emails for the registered orders. As said real programming!