Special delivery service

§ 6006. Special delivery service (a) When a special delivery fee is prepaid in addition to the regular postage the Postmaster General shall give the most expeditious handling and transportation practicable to mail of any class and immediate delivery within— (1) one mile of a post office; (2) one mile of substations or branches as the Postmaster General may designate; and (3) the delivery limits of a post office having carrier delivery service. (b) The postmaster is responsible for the immediate delivery of every special delivery article received at his office for delivery.