Just like other mailings, the transactional module generates Mailing Activity Reports (MARs) for all sent mailings. Here, you can see if recipients opened, clicked, or forwarded the mailing, as well as other statistics.
View a Transactional Mailing Report
Hover over the mailing's Menu icon and select Reports > View Activity.
A report for the selected mailing is generated.
The insights that you can glean about your transactional mailings from the Mailing Activity Report could be very valuable to your organization.