MAIL COVER

mail cover.A process by which the U.S. Postal Service provides a government agency with information on the face of an envelope or package (such as a postmark) for the agency’s use in locating a fugitive, identifying a coconspirator, or obtaining other evidence necessary to solve a crime. [Cases: Postal Service 47. C.J.S. Postal Service and Offenses Against Postal Laws §§ 64–65.]

[Blacks Law 8th]