Which of the following is a permissible method to ship COMSEC under certain circumstances?

Shipping COMSEC materials requires adherence to strict security protocols due to the sensitive nature of the information and equipment involved. USPS Express Mail is considered a permissible method for shipping COMSEC under certain circumstances because it provides a combination of speed and security that aligns with COMSEC policies.

USPS Express Mail is often used because it offers tracking capabilities and a level of service that ensures timely delivery, making it suitable for sensitive materials. The postal service also has specific handling procedures for classified and sensitive items, enabling compliance with necessary security requirements during transport.

While other options may also provide some level of service, they might not meet all the specific criteria established for shipping COMSEC materials, such as secure handling, traceability, or compatibility with proper safeguarding measures. Therefore, USPS Express Mail stands out as an appropriate choice in the context of COMSEC shipping practices.