This is a quick guide to walk you through the process on how to setup Approval Notification Emails.
To setup notification emails when an approval has been sent out, simply go into Tools and select System Configuration.
In User Setup, search and select the user to enable approval notification emails (In most cases you will choose yourself or the system admin).
Click on Edit.
In the People Manager Tab, search and select the person that you would like to enable Approval Notification Emails for.
Once chosen, check off the Approval Emails checkbox to enable notification emails.