On this page, you will learn how to know if your emails sent with Mail Merge for Gmail📣have been opened.
To activate tracking, simply tick "Track emails" in the add-on
activate email tracking
Tracking status will be available in your spreadsheet. When the email will be opened, the status will change from "Sent" to "Read" :
Example of an email tracked
Tracking status is updated when your Google Sheets is loaded, but you can refresh it at any time going to Menu / Extensions / Mail Merge for Gmail📣 / 🔄 Refresh tracking