Passport Application Tracking

Hello all,

I would like to know how does one find out if their Check & Send passport application has reached the passport office? For e.g., in the passport timeline page, there are two dates

Date of application:
Date of receiving the application:

While using Check & Send, how does one know whether the Passport Office have received their application. I have a receipt from the Post Office with a barcode. And no other tracking number or information.

Thank you.