§ 2104. Officer
(a)
For the purpose of this title, “officer”, except as otherwise provided by this section or when specifically modified, means a justice or judge of the United States and an individual who is—
(1)
required by law to be appointed in the civil service by one of the following acting in an official capacity—
(b)
Except as otherwise provided by law, an officer of the United States Postal Service or of the Postal Regulatory Commission is deemed not an officer for purposes of this title.