The statistics may not have been updated recently. Follow the below steps to update the statistics for your delivery.
  1. In the Email Campaign, select the Deliveries tab and find the delivery that you would like to update.
  2. Click the Review link under the Actions column.
  3. Click Update the statistics for this delivery under Related Actions from the left panel.
Note: Updating the statistics could take a little time depending on your house file size and server load (BB743650).