To begin log into ambari and from the Views section select workflow manager.
Now select create new workflow.
Give your workflow a name and then click on the line that connects the start and end nodes to add a step.
Select the email step to add it to your flow and then select it and click the settings(gear) icon.
Add your custom settings for all required fields and click save.
Now we have a workflow capable of sending an email. That was easy and no XML needed to be modified(big reason many people have never used Oozie)
Click Submit and provide a path (that doesn't already exist) for the workflow to be saved.
Now go to the Dashboard and find your submitted workflow.
You can click run from the dashboard to run the flow or you can select "run on submit" in the step before saving and submitting the flow.