To know the procedure of the transfer of mail when the mail is extracted from a division box of full accumulation.

CPU 20, when a fullness signal from the full accumulation sensor of a division box is received through an input port 25, flashes the LED for fullness of the division box through an output port 26, turns off the LED for fullness through an output port 26 when the mail of the division box is extracted and the fullness signal is turned off, flashes the LEDs for guide of the division box and a temporary preservation cabinet which can be transferred through the output port 26, turns off the LEDs for guide of the division box and the temporary preservation cabinet through the output port 26 when the detection signal of mail from the detection sensor of a temporary preservation box to which the extracted mail is transferred is received through the input port 25, and turns off all the LEDs for guide after two seconds through the output port 26.