US Postal Service

Kind of a one two combo on this question.
What is the official status of the US post office? Are they similiar to regualted utility?

Follow-up…
The ATF and USS come under the treasury Dept, the FBI comes under the Justice Dept.

Where do the US Postal Investigators get their authority from?

You should go to http://www.usps.gov for all the info, but
the USPS is a government run corporation.

Postal Inspectors get their authority from acts of Congress.