An e-mail sending and receiving system in which positional data about a plurality of places can be included in an e-mail message to be sent, and further detailed data can be obtained based on the included positional data, thereby improving the convenience and effectiveness of the positional data. The system includes a mail generating section for generating an e-mail message to be sent to an addressee; a positional data storage section for storing a plurality of positional data; and a positional data attaching section for attaching one or more of the positional data stored in the positional data storage section to the e-mail message generated by the mail generating section. The system may further include a section for generating detailed data relating to each positional data attached to the e-mail message, and attaching a URL for accessing the detailed data to the e-mail message.