C＃收到错误发送电子邮件

Question

  

错误：服务不可用，关闭传输通道。服务器响应为：资源暂时不可用 - 请稍后再试

private void button1_Click(object sender, EventArgs e)
{
    string smtpAddress = "smtp.mail.yahoo.com";
    int portNumber = 587;
    bool enableSSL = true;

    string emailFrom = "mail@yahoo.com";
    string password = "mailpass";
    string emailTo = "sendemail@yahoo.com";
    string subject = "Hello";
    string body = "Hello, I'm just writing this to say Hi!";

    using (MailMessage mail = new MailMessage())
    {
        mail.From = new MailAddress(emailFrom);
        mail.To.Add(emailTo);
        mail.Subject = subject;
        mail.Body = body;
        //mail.IsBodyHtml = true;
        // Can set to false, if you are sending pure text.

        // mail.Attachments.Add(new Attachment("C:\\SomeFile.txt"));
        //mail.Attachments.Add(new Attachment("C:\\SomeZip.zip"));

        using (SmtpClient smtp = new SmtpClient(smtpAddress, portNumber))
        {
            smtp.Credentials = new NetworkCredential(emailFrom, password);
            smtp.EnableSsl = enableSSL;
            smtp.Send(mail);

        }
    }
}

我该怎么办？

Answer 1

您需要确保外部应用程序有权通过您的电子邮件发送电子邮件，然后才能继续。