[MAIL] USPS 2016 International Box Truck for Cities: Skylines
To get between the sorting center and the post office, you don’t want to rely on the default post truck. It looks out of place in American cities. Fill the role with a conventionally styled International box truck, with the engine in front of the driver. Let it shuttle mail to and from the facility.
This truck does SPAWN as MAIL TRUCK. I tested this in vanilla with Service Vehicle Selector 2
Use Service Vehicle Selector to set postal vehicles types for your postal depots/office.