Which entity is responsible for maintaining inventory control of mail ensuring it is processed on a first-in, first-out basis?

The Mail Control Activity (MCA) is responsible for maintaining inventory control of mail and ensuring it is processed on a first-in, first-out basis. This function is crucial for efficient mail handling, as it helps to prevent delays in delivery and ensures that older mail does not remain unprocessed for extended periods. The FMC also implements tracking and accountability measures for incoming and outgoing mail, contributing to overall postal efficiency and reliability.

In contrast, other entities listed, such as the Military Postal Service, primarily focus on the logistics and operation of mail delivery within the military framework, rather than on inventory control processes. Aerial Mail Terminals (AMTs) are specialized facilities involved in handling air mail and may not engage in comprehensive inventory management, while Official Mail Centers deal with the processing and distribution of official military mail but do not specialize in the inventory control methods that the MCA employs. Thus, the MCA is uniquely positioned to manage mail inventory effectively while adhering to the first-in, first-out principle.