Tom,
This can easily be done with a Workflow Rule where you run the Rule on the Request Item Type and based on Logic/Criteria set by you, you would set action=Send Email and specify who you want the email sent to and Email content (Subject/Body).
You can take a look at some of the pre-built Notifications available in our Notification Manager App here...
http://www.clarizen.com/appsmarketplace/item/Email-Notification-Manager.html
Also, For further clarification, we suggest you register for one of our daily Q&A webinars (see the link-> http://www.clarizen.com/resources/online-demo.html#second ).These are great resources for free consulting with our Customer Success Managers and visual answers to your questions.
Sincerely,
Boris