Hello, I need to have a question clarified by a China Post employee:

In the example image below, the tracking number starts with CX and it is labeled as Priority Mail International which is not the same service as EMS in the USA.

In this next example image below, the tracking number starts with EA and it is labeled as Priority Mail Express International which is EMS in the USA.

1. In China Post, what is the name of the service for tracking numbers that start with CX?

2. What are the differences in service between tracking numbers that start with CX and tracking numbers that start with EA?

3. Does is cost less to ship a package with the service designated by tracking numbers that start with CX than it does to ship a package with a tracking number that starts with EA?

If they are the same, why is the one that starts with EA referred to as "Express" on the tracking, and the one that starts with CX is not referred to as Express?

it doesn't seem like that. My US postal service clearly differentiates between packages with CX tracking number and packages with EA tracking number. Only the EA is treated as "Express"
So, for China Post, EA means EMS. What does CX mean? It must be something different than EMS?