To allow a receiver of e-mail addressed to a plurality of destination addresses to readily specify a message of his/her interest included therein. A device for processing e-mail containing a plurality of destination addresses, contents corresponding respectively to the destination addresses, and display attributes for displaying the corresponding contents on a display device is provided. The e-mail processing device includes a unit for acquiring the degree of association between a first destination address, which is one of the plurality of destination addresses and at least one of the other destination addresses, and a unit for modifying the display attributes for the contents in accordance with the degree of association.