Go to Reports > Submissions
Under the 'Primary Report' header, click on the 'Submission Status Report'
Under the 'Other' header, filter by Completed = Yes, Accepted = Yes (or 'No' to send reject emails), and click 'Run Report'
On the results screen, click 'Send Email'
Select the Email Template you wish to send, or select 'Blank' to create one from scratch, and click 'Submit'
Review/edit the email and list of recipients before clicking 'Send' (NOTE: The email will go to the Submitter unless you use the 'Person Roles to CC' option)
Click 'OK' if you are sure you want to send the email