It pretty much failed, mostly due to a failure of Congress to provide suitible capital support.
UPS, on the other hand, was a local package and furniture delivery business in Seattle. Some Post Office Department managers who were upset that Congress wouldn't support their scheme to "fix" parcel delivery for once and all, bought it out and turned it into today's UPS. First thing they did was dump the furniture moving part.
Fed Ex is pretty much the idea of a fellow who borrowed it from his roommate in college whose father, the postmaster of Gary, Indiana, had come up with it.
Mail delivery really shouldn't mix with parcel delivery, or furniture moving.