Ok, so it is not a news story, it is not a new story either, but it is something to consider given all of the claims that USPS is so efficient and provides the cheapest service that free market cannot provide.
USPS did have that challenge and USPS failed in it and it turned to government in order to drive the challenger out of the market with lawsuits and pro-government monopoly laws. The challenge came in a form of an Anarchist, Lysander Spooner, who started his own post mailing business back in January 11, 1844. The name of the business was Lysander Spooner's American Letter Mail Company.
The USPS in fact engaged in behaviour, that many anti-free marketers assign to private businesses.
Hoping to drive Spooner out of business without raising any constitutional questions, the Postmaster General resorted to some extra-legal measures. Transport companies were told that they would lose their government contracts unless they stopped carrying American Letter Mail Company mail.
What is interesting is that the USPS postage prices were set by the Congress, not by market forces, and so it took Congress to cut USPS prices in near half, from 25 cents for a single sheet of paper as one of the responses to Lysander Spooner entering that market and providing the same service at lower prices. By cutting the USPS prices in half, Congress forced Spooner out of the business.
As a consequence of lower prices, USPS business rose significantly and rates were reduced again in 1851, which shows by the way, that an economy of scale makes more profit from higher volume even if this volume increase comes as a consequence of lowering prices.
This is another example of how it is the government, that creates monopolies and private sector that produces better products at cheaper rates. Of-course the government monopolies eventually fail as the entire underlying system becomes corrupt and can no longer sustain the costs associated with running subsidised monopolies.