1. Open Rate: The percentage of recipients who open the email. 2. Click-Through Rate (CTR): The percentage of recipients who click on a link within the email. 3. Conversion Rate: The percentage of recipients who complete a desired action, such as making a purchase. 4. Bounce Rate: The percentage of emails that were not successfully delivered. 5. Unsubscribe Rate: The percentage of recipients who opt out from the email list.