I want to build a function that will return all of the email addresses from column D in one Google Spreadsheet that are not present in column D of a different Google Spreadsheet.
This could be in the form of a function that runs automatically once a day, or it could just be manually refreshed- either way is fine.
Email addresses will not correspond to the same row in each sheet, the columns in each sheet are populated from two completely different forms. So I need to compare both entire columns, and spit out the email addresses from Spreadsheet1 column D that aren't in column D of Spreadsheet2.