18 U.S.C. § 1726 : US Code - Section 1726: Postage collected unlawfully

Search 18 U.S.C. § 1726 : US Code - Section 1726: Postage collected unlawfully

Whoever, being a postmaster or other person authorized to receive
the postage of mail matter, fraudulently demands or receives any
rate of postage or gratuity or reward other than is provided by law
for the postage of such mail matter, shall be fined under this
title or imprisoned not more than six months, or both.