From the docs:
CREATING A ROLLOUT CONFIGURATION
Create a rollout configuration when the installed rollout configurations do not meet your application requirements. Create the rollout configuration, then add the trigger and synchronazion actions. The new rollout configuration is available when setting rollout configurations on a blueprint or on a Live Copy page.
The following events are available to use as synchronization triggers:
- On Rollout: The blueprint page is rolled out.
- On Modification: The source page is modified. Be careful when choosing this option as it might cause a lot of network traffic.
- On Activation: The source page is activated.
- On Deactivation: The source page is deactivated.
See: http://dev.day.com/docs/en/cq/current/administering/multi_site_manager.html
You can write an event handler that is fired when one of these events occur. You can easily write a custom email service for CQ that is invoked from the event handler:
See this for creating a custom CQ email service:
http://helpx.adobe.com/experience-manager/using/creating-custom-cq-email-services.html
See this community article on how to write an general event handler:
http://helpx.adobe.com/experience-manager/using/events.html
From you event handler - code it so it calls the email service and sends email to whom you want.