A mail collection point-of-use for and method of preventing detected hazardous materials within a mail collection point-of-use from contaminating components of subsequent mail delivery system processes. The mail collection point-of-use comprises a mail drop unit having an opening for receiving customer-deposited mail, a mail receptacle for accumulating received mail, an enclosure coupled to the mail drop unit and containing the mail receptacle and having a door that seals an opening large enough to permit removal of the mail receptacle, a detector inside the enclosure, which generates a detection signal upon detection of airborne hazardous material, and an indicator outside the enclosure for indicating the detection of hazardous material. By indicating the detection of hazardous materials within the mail collection point-of-use before removing the mail receptacle and its contaminated mail, the further spread of the hazardous materials in a mail delivery system may be prevented.