1. Go to Contacts > Individuals > Click Advanced Search 
  2. Expand Contacts > Profile > Contact Fields
  3. Click Email and click Add
  4. Select Email Not Empty and click Ok
  5. Expand Contacts > Activities
  6. Click Activity Name and click Add
  7. Select Activity Name = HTML Email Opened
  8. Under Additional Filters, mark Activity Date and select the date you want
  9. Click Ok
  10. Ensure the second line of the query is highlighted then click Not
  11. Click Save to Query Library
  12. Specify Library Name, click Submit
  13. Click Run Query
At this point you can Print and/or Export (Excel or CVS file) your results. To view a report for a specific mailing.