Sealed mail definition
Sealed mail means mail on which appropriate postage is paid, and which, under postal laws and regulations, is included within a class of mail maintained by the Postal Service for the transmission of letters sealed against inspection, including First-Class Mail, Priority Mail, Express Mail (domestic and international), Mailgram messages, Global Express Guaranteed Document service, Global Priority Mail service, International Priority Airmail service, international Letter Post Mail other than International Surface Airlift service and Publishers’ Periodicals, and international transit mail.