1. An image processing apparatus connectable to a network, comprising: a holding unit configured to hold a first address book indicating transmission destination of data and first set information for operating the image processing apparatus; a receiving unit configured to receive a second address book and second set information which is held in another image processing apparatus and transmitted from the other image processing apparatus; an acceptance unit configured to accept a selection of a user to select one from a group comprising: setting of allowing both the first address book and the first set information held by said holding unit to be updated by the second address book and the second set information held in the other image processing apparatus, setting of allowing the first address book held by said holding unit to be updated by the second address book held in the other image processing apparatus and inhibiting the first set information held by said holding unit to be updated by the second set information held in the other image processing apparatus, and setting of inhibiting the first address book held by said holding unit to be updated by the second address book held in the other image processing apparatus and allowing the first set information held by said holding unit to be updated by the second set information held in the other image processing apparatus; and an updating unit configured to update the first address book and the first set information held by said holding unit in accordance with the selection accepted by said acceptance unit.