Short Answer 
To transmit Secret information securely, it is essential to use registered mail with a receipt for traceability and proof of delivery. Avoid using external collection boxes for sensitive materials and be cautious with options like waivers of signature that may compromise security.
Step 1: Understand the Registered Mail Requirement
When transmitting Secret information, it is mandatory to use registered mail with a receipt. This ensures that the delivery method is both secure and traceable, minimizing the risk of tampering or loss. The registered mail receipt acts as proof of delivery, confirming that the information reached its intended recipient.
Step 2: Know the Restrictions on Collection Boxes
Be aware that while there are regulations concerning the use of external street-side collection boxes, these do not specifically pertain to the transmission of Secret information. It’s crucial to follow appropriate channels and methods to ensure the security of sensitive materials without relying on potentially insecure external collection methods.
Step 3: Clarify Signature and Indemnity Options
In certain scenarios, you may encounter the option of a waiver of signature and an indemnity block when sending mail. However, this option does not typically apply to the transmission of Secret information and should be avoided to maintain security and accountability in communications.