Postal service is Constitutionally mandated.
Then we need a Constitutional Amendment so that the whole sorry mess can be privatized!
Along with 'post roads', the Federal Highways.
The Federal Highways (post roads) are constructed and maintained by private contractors. The Post Offices can be run the same way. I've lived in several places where the community post office was operated inside and by the local grocery store. It works just fine. Great service.