This is a Google Sheets™ Add-on for the Form Responses from a Google Form™. The Form must require email addresses. Insert a sheet into the Form Responses with a list of the expected participants. One of the columns MUST contain email addresses and have a column header that contains the word email. Missing From by Alice Keeler automatically detects the Email Addresses column on the Form Responses tab and matches it to the email column in the active sheet. 

Note: The Form Responses tab must start with the word Form.