Actually, when I was relying on SmartPost for my former small business and I, too, didn’t understand why I would send out items using a SmartPost label sure it was via FedEx only to find it would post as USPS.
After a few minutes of research and asking the very very busy staff I found that it’s FedEx who hands off packages TO USPS.
Here is a the example the owner was talking about:
“FedEx SmartPost, which is similar to UPS SurePost, is a hybrid shipping service with which FedEx will pick up packages from the shipping destination,
and then hand the packages off to the U.S. Postal Service (USPS) for the final delivery to the end customer.
“What’s unique about SmartPost is that there are two different carriers (FedEx and USPS) handling every package.
“One of the reasons this service was created is that, each day, the USPS is already visiting nearly every address in the United States to deliver mail, so there is efficiency and little-added cost for USPS to deliver small packages to residences, which is not necessarily the case with FedEx and UPS.”
I hope this helps and apologize – I understand the confusion and frustration. It is not the shop’s fault. It’s purely a FedEx/USPS deal :)