Mail Receipt allows you to know who open your emails sent from Gmail!
How to use it ?
Install the add-on from the Google Marketplace by clicking here!
Once installed, launch the add-on using the right menu and authorise the add-on
Start a new mail and click on the Mail Receipt button to enable the monitoring
Use the right sidepanel to retrieve your tracking spreadsheet and see who opens your email!
The document will let you know when your emails are viewed:
