使用 asp.net 发送邮件失败。连接主机未能响应

Question

我想从我的 c# 应用程序发送一个简单的测试邮件

我正在使用以下代码

MailMessage mail = new MailMessage("from", "to");
mail.Subject = "TestEmailImportant";
mail.Body = "This mail is to test if this program is working";

SmtpClient smtpClient = new SmtpClient("smtp.gmail.com", 587);
smtpClient.Credentials = new System.Net.NetworkCredential()
{
    UserName = "xxxxxxxxx@gmail.com",
    Password = "xxxxxx"
};
smtpClient.EnableSsl = true;
smtpClient.Send(mail);
Label1.Text = "Email Sent";

这是在单击按钮时触发的。

每当我单击按钮时，浏览器都会一直“等待主机”，大约一分钟后我会收到此错误

连接尝试失败，因为连接方没有 一段时间后正确响应，或建立连接 失败，因为连接的主机未能响应“某些 IP”。

指向smtpClient.Send(mail); 线。

Answer 1

注册 Gmail 并转到https://www.google.com/settings/security/lesssecureapps，您可以在其中查看设置。 访问不太安全的应用程序

Turn off (default) ==> Turn On    

添加此代码后，

  MailMessage mail = new MailMessage("fromm@gmail.com", "toaddress@gmail.com");
                mail.Subject = "TestEmailImportant";
                mail.Body = "This mail is to test if this program is working";

                SmtpClient smtpClient = new SmtpClient("smtp.gmail.com", 587);

                smtpClient.Credentials = new System.Net.NetworkCredential()
                {
                    UserName = "XXXXXX@gmail.com",
                    Password = "YYYYYYYY"
                };

                smtpClient.EnableSsl = true;
                System.Net.ServicePointManager.ServerCertificateValidationCallback = delegate(object s,
                        System.Security.Cryptography.X509Certificates.X509Certificate certificate,
                        System.Security.Cryptography.X509Certificates.X509Chain chain,
                        System.Net.Security.SslPolicyErrors sslPolicyErrors)
                {
                    return true;
                };

                smtpClient.Send(mail);