Organizations can optionally track opens for System Emails. Tracking is enabled for emails individually. When tracking is turned on for the email, you'll see an additional Results icon in the Maintain Column showing the detailed send and open data for the email.
Turning on Tracking
Find the System Email you want to track, then click the Configure (wrench) icon.
Check the box to Track Opened Emails, then click Save.
Tracking Opens
When Tracking is turned on for an email, you'll see a Results icon in the Maintain Column. Click the icon to search for open records in a specific date range.