Some key items of interest:
By 1966 the Military Post Office Center (formerly the Directorate of Military Post Office) controlled 29 post annexes which served more than 1,500 KBC units and addresses. In 1973 there were 40 annexes servicing more than 3,000 KBC units.
The most frequent shortcoming in the military postal service was the time the mail took to reach the responsible person or beneficiary. An extensive investigation .... revealed that the delay did not take place between one KBC and another as many servicemen had thought, but primarily between the sending unit and the original KBC or annex, and between the destination KBC or annex and the receiving unit. The delay was also caused by the unit's internal distribution system.
There was also a lack of coordination between the unit and the area logistics command to have the KBC changed in case of [a] long-term operation outside the military region.
As for mail security, several measures were taken to prevent loss or interception. Mailmen, with proper security clearances, were chosen from good and reliable personnel. Each mailman was issued a register to record the receiving and delivery of mail, which was daily inspected by the chief of the mail and message section. Each mailman was also issued a leather case with lock for carrying mail in transit.
The book was reprinted by and is available from Dalley Book Service in Virginia. They have also reprinted a number of other military titles, including Bernard Fall's The Viet Minh Regime and Documents Relating to British Involvement in the Indo-china Conflict 1945-1965 originally published by Her Majesty's Stationery Office. Tell George I sent you!