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.

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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.

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