Patent ID: 8566591

Claim:
An e-mail sending method, comprising the steps of: disclosing a receiver's public address; sending, via a sender's mail server BMS, the public address and a message M B for requesting a permission of communication with a sender to a receiver's mail server AMS; causing the mail server AMS to send the message M B to a receiver; causing the mail server AMS to receive an address issuance permission from the receiver who received and read the message; computing a value [A, B, N]K which is encrypted by the mail server AMS with a secret key K of the mail server AMS from a receiver's identifier A, a sender's identifier B, and a nonce N issued by the mail server AMS, and sending the value [A, B, N]K to the sender via the mail server BMS; and forming an e-mail address (LD address) by attaching a receiver's domain name to the encrypted value [A, B, N]K, and sending an e-mail to a receiver.