Email non-submitters gives you the ability to email students within a class that haven't already submitted. You can send a reminder email anytime during the submission process - including once the post date has passed to warn late submitters.
1. Navigate to the Assignment Inbox for the class you would like to email
2. Click on the Email Non-submitters link to the right of the Assignment Inbox
3. Enter a subject line and message for the email
4. Click the Include me checkbox if you'd like to also receive a copy of the email that your students will
5. Click the Send button to email your students