A communication terminal having an email message sending-and-receiving function includes an email-message history information storing unit configured to store email-message information of at least a sent email message as email-message history information, an intended-to-be-sent email message storing unit configured to store email-message information of an intended-to-be-sent email message, the intended-to-be-sent email message being an email message which is going to be sent, as intended-to-be-sent email message information, a destination-address right/wrong determining unit configured to determine whether a destination address of the intended-to-be-sent email message is right or wrong by comparing the email-message history information with the intended-to-be-sent email message information, and a unit configured to send, if the destination address is determined to be wrong, a notification of the wrong destination address to a user and to request the user to check the destination address.