您需要提供您的邮件服务器的主机和端口信息、发送器和接收器邮件地址，多数情况下都需要的服务器验证信息。

You will need to supply host and port information for your mail server, sender and recipient email addresses, and, in most cases, server authentication information.

youdao

安全多用途Internet邮件扩展（Secure Multipurpose Internet Mail Extensions，S/MIME）允许将数字签名附加到电子邮件消息上，这样接收方就可以验证签名者的身份。

Secure Multipurpose Internet Mail Extensions (S/MIME) allows digital signatures to be attached to e-mail messages, such that the recipient can verify the identity of the signer.

youdao

安全多用途Internet邮件扩展（Secure Multipurpose Internet Mail Extensions，S/MIME）允许将数字签名附加到电子邮件消息上，这样接收方就可以验证签名者的身份。

Secure Multipurpose Internet Mail Extensions (S/MIME) allows digital signatures to be attached to e-mail messages, such that the recipient can verify the identity of the signer.

youdao