I don't know how to interpret the underlined sentence.
Regarding the email you sent yesterday, the details are as follows:
1. We had booked the inspection for 1242 pcs for May 05 and 1640 pcs for May 13. However, Angel has requested that we split the inspection quantity into smaller lots in order to make sure the goods are of the best quality.
2. We pushed back the shipment date to allow the factory to meet the schedule on time. Therefore, 16400 pcs will be ready for inspection by the end of April, booked previously on May 15. Until Susan informs Sandy that your US office is required to ship them earlier, due to the shortage. Therefore, we rescheduled them from May 15 to 05 in order to fulfill your US requirement.
Thank you for your prompt and kind reminder. We will continue to try to meet your needs in the future.
Student or Learner