domain mapping notifcation

Howdy all,
Just wondering if there is an easy way to get an email notifation for when a client maps a domain. As for the time being I need to park the domain to get it to work.
For the moment I'm just going to ask clients to let me kow but would be nice if the notifation was automated, though will be even nicer once I get my service upgraded with my host and everything is completly automated.
Cheers,
D