Question

我收到此错误

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Must issue a STARTTLS command first. e17sm974159fak.34

的Web.config

<mailSettings>
    <smtp deliveryMethod="Network"
                from="emailaccount@gmail.com">
        <network defaultCredentials="false" host="smtp.gmail.com" port="587"
                    userName="emailaccount@gmail.com"  password="12345678" />
    </smtp>        
</mailSettings>

代码文件

public void Submit()
        {
            EnsureCurrentlyValid();
            // Send via email
            var message = new StringBuilder();
            message.AppendFormat("Date: {0:yyyy-MM-dd hh:mm}\n", DateTime.Now);
            message.AppendFormat("Email from: {0}\n", Name);
            message.AppendFormat("Email: {0}\n", Email);
            message.AppendFormat("Message: {0}\n", Message);
            SmtpClient smtpClient = new SmtpClient();
            MailMessage m = new MailMessage(
                "visitor@mydomain.com", // From
                "emailaccount@gmail.com", // To
                "Suggestion/Comments", // Subject
                message.ToString()); // Body

            smtpClient.Send(m);
        }

Answer 1

尝试将EnableSsl属性设置为true：

smtpClient.EnableSsl = true;

AFAIK此属性只能在代码中设置，不能在配置文件中指定。

Answer 2

实际上，您可以通过添加enableSsl =“true”在web.config文件中处理此问题。这对我有用，我不需要在代码中做任何事情。

e.g。

<network host="smtp.gmail.com" enableSsl="true" ... />

Answer 3

这对我有用：

需要在Google帐户上打开“访问安全性较低的应用程序”（来自电子邮件）。
设置smtpclient.UseDefaultCredentials = false;

设置smtpclient.EnableSsl = true;

    MailMessage mail = new MailMessage("FromEmail_Address", "ToEmail_Address");
    SmtpClient smtpclient = new SmtpClient();
    smtpclient.Port = 587;
    smtpclient.DeliveryMethod = SmtpDeliveryMethod.Network;
    smtpclient.UseDefaultCredentials = false;
    smtpclient.Host = "smtp.gmail.com";
    smtpclient.UseDefaultCredentials = false;
    mail.Subject = "Email Subject";
    mail.Body = "Content of the email";
    smtpclient.EnableSsl = true;
    smtpclient.Credentials = new System.Net.NetworkCredential()
    {
        UserName = "FromEmail_Address",
        Password = "password of the email"
    };
    client.Send(mail);

SMTP服务器需要安全连接或客户端未经过身份验证

3 个答案: