Why were some ACS scans not returned back to the Mail360 Data Manager/EngageOne Delivery Audit Hub from the USPS

Product Affected:  MAIL360 Data Manager™/EngageOne™ Delivery Audit/EngageOne™ Inform
Product Feature: General

Using MAIL360 Data Manager™/EngageOne™ Delivery Audit/EngageOne™ Inform, some of the Address Change Service (ACS) scans are not returned back to the Hub from the USPS or found in the ACS reports.  They were not in the unmatched table either.   Is there a reason why some intelligent mail barcode (IMB) records were not returned?
After checking with the USPS PostalOne team, here was their answer:
“We have completed the investigation into. These COA and Nixie records were not provisioned to any mailer, because the Rate Category on the pieces was Basic (1c/4c Presort) and did not meet the automation requirements. The Rate Category, Mail Class, and Processing Category combination must be considered automation in order for the COA/Nixie records to be provisioned to a mailer.
For example, IMB 0014112345612345767521204 from would have needed to have a Rate Category of 5 Digit Barcode, 3 Digit Barcode, AADC BC, MxAADC BC, or ADC BC for the Nixie record to be provisioned.”
With this explanation, it means only full service IMB Automation mail pieces are returned for this First Class Letter presort according to the Informed Visibility® Mail Tracking & Reporting rules.  If the mail piece is presorted at Basic(not Automation) or is a Basic IMB because the zip plus 4 or Delivery point is missing, it will not be part of Full Service.
Here is another example of why ACS scans are not returned, the USPS PostalOne team, provided this answer::

For these IMbs (0014112345628998900612345175499 and 0014112345629008908012345231452), the Mail Class, Mail Category, and Rate Category are indeed automation. However, there has not been any COAs or Nixies associated to these pieces. Therefore, there are no ACS records to provide.
Please let us know if there are any additional questions.
SASP Support"

UPDATED:  September 18, 2018