传统电子邮件业务使用明文方式传送电子邮件，一旦窃听者捕获电子邮件报文，通过对邮件报文进行分析就能获取邮件内容。尽管当前存在一些解决方案能够提高电子邮件的 安全性能，但只要窃听者拥有足够的计算能力，数据安全仍无法保证。针对上述问题，提出了一种基于量子信道通信的邮件传输系统。在邮件传输过程中， 将量子信道与传统信道结合使用，建立基于量子传输的SMTP协议和POP3协议。最终仿真结果表明，当邮件内容数据长度达到30比特时，量子邮件内容被窃取的可能性接近于0。 因此，与传统的电子邮件传输系统相比，量子通信邮件传输系统能够保持较好的安全性能。

Traditional email business uses the plain text to transfer the mail content. If the eavesdropper captures the data packets and owns enough computing capability, he will easily analyze the data. Therefore the data might be leaked. Although there are some solutions that could increase the security performance of email, the insecurity factors still remain. To solve the above problem, a quantum mail transfer system is proposed to transfer the main data based on quantum channel. Combining quantum channel with traditional channel and establishing quantum SMTP protocol, POP3 protocol in email transportation process insure email security. The simulation analysis showed that the exposed probability of quantum email is closer to 0 when the length of mail data is near to 30 bit. So, even if the eavesdropper owns enough computing, the quantum mail transfer system owns better secure performance.