From Reports > Scorecard Results tab you can view jobs that have not provided a scorecard response yet, and you then have the option to requeue/resent the Scorecard email.
To find customers who have not completed the scorecard for a specific job, uncheck the box that says Only Show Responses. Enter the date range of your choice, and click Update. You will now see the button to Requeue Scorecard.
Click Requeue Scorecard. Message changes to Email Queued.
All scorecards get queued to be sent. There's a background job that processes the queue every 15 minutes.