随着电子邮件的逐渐普及，通过电子邮件传递机密信息也在迅速增加。因此，对电子邮件的安全性提出了更高的要求。电子邮件的安全性包括电子邮件的真实性和保密性。真实性是指对发送者的确认，即该邮件的确是某人发出的，同时也可以防止发送者不认帐。保密性是指对邮件进行加密 With the increasing popularity of e-mail, the transmission of confidential information by e-mail is also rapidly increasing. Therefore, the security of e-mail put forward higher requirements. E-mail security includes the authenticity and confidentiality of e-mail. Authenticity is the confirmation of the sender, that is, the message is sent by someone, but also to prevent the sender does not recognize the account. Confidentiality refers to encrypting mail