The present invention discloses a mail sending method and an email system and relates to the field of internet communications. The method includes: receiving a mail sending request which carries a mail template filled out by a sender; encapsulating the mail template into an anonymous mail that includes no receiver mailbox ID and no sender mailbox ID; and obtaining a receiver mailbox ID and delivering the encapsulated anonymous mail to a mailbox corresponding to the obtained receiver mailbox ID. The email system includes: a receiving module, an encapsulating module, and a delivering module. The present invention enables a sender to send an anonymous mail to a stranger whose mailbox address is unknown to the sender and provides a service for users to talk about privacy issues.