You may want to know what steps are taken for the Acknowledgement status to be changed from Not Acknowledged to Acknowledged.
The acknowledgment status would change when the payment is pulled into the acknowledgment process. The Acknowledgment status field, is tied to the Acknowledgment process in Marketing and Communications. If you have a letter in your Acknowledgment process that is set up to pull these payments in, when the process is run the payments would pull in and be acknowledged by the specific letter you have set up.
Click here to see How to run Acknowledgment letters