The Postal Service is mandated to provide universal service to every address in the US, a few select international addresses, and is allowed to operate at a deficit.  Currently it is about 30 billion dollars in debt, but it is expected to make a profit in the near future.
assitant
Yes.  To be transparent and show financial results to taxpayers, it needs to make a profit.  This requirement ensures that services are provided and costs are reasonable, rather than subsidized by taxpayers.
assistant
Is the USPS actually mentioned in the Constitution?
user
Yes, it is.  Article 1, Section 8 of the Constitution defines the postal system of the United States.  The Postal Service was not established as an independent agency until 1792.
assistant
Is it supposed to turn a profit?
user