Why is posting a business letter not usually a secure communication channel?

Posting a business letter is not usually a secure communication channel because it can be easily intercepted or accessed by unauthorized individuals during transit. Letters can be lost, stolen, or tampered with, exposing sensitive information to potential threats. Additionally, postal services do not provide tracking or encryption, making it difficult to ensure the confidentiality and integrity of the contents. As a result, more secure methods, such as encrypted emails or secure file sharing, are often preferred for sensitive communications.