Because the send did not complete message send ID and stats will not be generated. If you follow the steps below you should be able to receive information on how many constituents received this message in the previous send.

  1. Send that very same message back to draft status
  2. Make the necessary edits
  3. Approve the message
  4. Click Set Up Delivery
  5. Chose the same Target Audience and Do Not Email groups used in the previous send
  6. Click Calculate Audience Recipients.

After the calculation is complete under Filters applied you can see how many constituents were filtered out due to having received previously.