A storage medium storing a mail management program, the mail management program causing a computer to execute: receiving from a first user, a designation of a first electronic mail addressed to the first user as an open mail, which is made open to a second user, first setting a receiving date and time at which the designation is received as date and time information corresponding to the open mail, second setting another receiving date and time at which a second electronic mail which is not the open mail and is addressed to the second user is received by the computer, as the date and time information corresponding to the second electronic mail and outputting, upon receipt of an output instruction from the second user, the open mail and the second electronic mail in accordance with the date and time information.