Use of excessive amount of postage stamps. The sender is unknown. No return address. The addressee normally does not receive personal mail at the office. Name and title of addressee are not accurate.
Mailing emits a peculiar odor.
Mailing appears to have been disassembled or reglued. Handwriting appears distorted or foreign. Protruding wires, tinfoil, or string are present. Pressure or resistance is noted when removing the contents. Outer container has irregular or asymmetric shape or has soft spots or bulges.