Email Detailed and Email Summary reports exist to help you determine how your emails are performing. The email campaign summary report yields all of the relevant statistics pertaining to particular email document (including the number of times it was sent out, to whom it was sent, and statistics on which customers opened it and which customers clicked links contained in the email).
As you start to get your feet wet with our email system, you’ll find that these statistics can be invaluable sources of information for purposes of tweaking your campaigns to gain the best conversion rates.
You may even want to consider doing A/B Testing—sending one version of your email to a particular group, and a slightly different email to a different group (changing variables such as the email subject line, the call-to-action, etc.) and compare response rates.