C# 无法在c中使用smtp发送电子邮件#

我想我的系统发送电子邮件时，一个按钮被点击，但我不断得到一个问题在smtp。发送（消息）每次，没有错误或任何事情，它只是一种冻结，虽然它仍然在运行。我写了4次尝试，都没有成功

第一次尝试：

try
{
    MailMessage mail = new MailMessage();
    SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com");

    mail.From = new MailAddress("robinx0852@gmail.com");
    mail.To.Add("robinx0852@gmail.com");
    mail.Subject = "Test Mail";
    mail.Body = "This is for testing SMTP mail from GMAIL";

    SmtpServer.Port = 25;
    SmtpServer.Credentials = new System.Net.NetworkCredential("username", "password");
    SmtpServer.EnableSsl = true;

    SmtpServer.Send(mail);
    MessageBox.Show("mail Send");
    MessageBox.Show("Email sent successfully");
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

try
{
    //string s = $"User {edtID} has failed to login";

    MailMessage message = new MailMessage();
    message.To.Add("robinx0852@gmail.com");
    message.Subject = "Employee login failure";
    message.From = new MailAddress("armeepatel@gmail.com");
    message.Body = "Hello";
    SmtpClient smtp = new SmtpClient("smtp.saix.net");
    smtp.Send(message);
    MessageBox.Show("mail Sent");
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

SmtpClient smtp = new SmtpClient();
smtp.Port = 25;
smtp.Credentials = new System.Net.NetworkCredential("username", "password");
smtp.EnableSsl = true;
MailMessage mailMessage = new MailMessage();
mailMessage.To.Add(new MailAddress("mymail@gmail.com", "ME"));
mailMessage.Subject = "Some Subject";
mailMessage.Body = "Test";
smtp.Send(mailMessage);

// string s = $"User {edtID} has failed to login";
MailMessage mail = new MailMessage();
SmtpClient SmtpServer = new SmtpClient();
mail.To.Add("mymail@gmail.com");
mail.From = new MailAddress("hotelfrontdesk@testhotel.com");
mail.Subject = "Employee login failure";
mail.IsBodyHtml = true;
mail.Body = "Hello";
SmtpServer.Host = "smtp.saix.net";
SmtpServer.Port = 25;
SmtpServer.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
try
{

    SmtpServer.Send(mail);
}
catch (Exception ex)
{
    MessageBox.Show("Exception Message: " + ex.Message);
    if (ex.InnerException != null)
        MessageBox.Show("Exception Inner: " + ex.InnerException);

}

var sysLogin = "yourlogin@gmail.com";
var sysPass = "y0urP@ss";
var sysAddress = new MailAddress(sysLogin, "Message from me!");

var receiverAddress = new MailAddress("mymail#gmail.com");

var smtp = new SmtpClient
{
    Host = "smtp.gmail.com",   //gmail example
    Port = 587,
    EnableSsl = false,
    DeliveryMethod = SmtpDeliveryMethod.Network,
    UseDefaultCredentials = false,
    Credentials = new System.Net.NetworkCredential(sysLogin, sysPass)
};


using (var message = new MailMessage(sysAddress, receiverAddress) { Subject = "Some subject", Body = "Some text" })
{
    smtp.Send(message);
}
MessageBox.Show("Success");

第二次尝试：

try
{
    MailMessage mail = new MailMessage();
    SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com");

    mail.From = new MailAddress("robinx0852@gmail.com");
    mail.To.Add("robinx0852@gmail.com");
    mail.Subject = "Test Mail";
    mail.Body = "This is for testing SMTP mail from GMAIL";

    SmtpServer.Port = 25;
    SmtpServer.Credentials = new System.Net.NetworkCredential("username", "password");
    SmtpServer.EnableSsl = true;

    SmtpServer.Send(mail);
    MessageBox.Show("mail Send");
    MessageBox.Show("Email sent successfully");
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

try
{
    //string s = $"User {edtID} has failed to login";

    MailMessage message = new MailMessage();
    message.To.Add("robinx0852@gmail.com");
    message.Subject = "Employee login failure";
    message.From = new MailAddress("armeepatel@gmail.com");
    message.Body = "Hello";
    SmtpClient smtp = new SmtpClient("smtp.saix.net");
    smtp.Send(message);
    MessageBox.Show("mail Sent");
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

SmtpClient smtp = new SmtpClient();
smtp.Port = 25;
smtp.Credentials = new System.Net.NetworkCredential("username", "password");
smtp.EnableSsl = true;
MailMessage mailMessage = new MailMessage();
mailMessage.To.Add(new MailAddress("mymail@gmail.com", "ME"));
mailMessage.Subject = "Some Subject";
mailMessage.Body = "Test";
smtp.Send(mailMessage);

// string s = $"User {edtID} has failed to login";
MailMessage mail = new MailMessage();
SmtpClient SmtpServer = new SmtpClient();
mail.To.Add("mymail@gmail.com");
mail.From = new MailAddress("hotelfrontdesk@testhotel.com");
mail.Subject = "Employee login failure";
mail.IsBodyHtml = true;
mail.Body = "Hello";
SmtpServer.Host = "smtp.saix.net";
SmtpServer.Port = 25;
SmtpServer.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
try
{

    SmtpServer.Send(mail);
}
catch (Exception ex)
{
    MessageBox.Show("Exception Message: " + ex.Message);
    if (ex.InnerException != null)
        MessageBox.Show("Exception Inner: " + ex.InnerException);

}

var sysLogin = "yourlogin@gmail.com";
var sysPass = "y0urP@ss";
var sysAddress = new MailAddress(sysLogin, "Message from me!");

var receiverAddress = new MailAddress("mymail#gmail.com");

var smtp = new SmtpClient
{
    Host = "smtp.gmail.com",   //gmail example
    Port = 587,
    EnableSsl = false,
    DeliveryMethod = SmtpDeliveryMethod.Network,
    UseDefaultCredentials = false,
    Credentials = new System.Net.NetworkCredential(sysLogin, sysPass)
};


using (var message = new MailMessage(sysAddress, receiverAddress) { Subject = "Some subject", Body = "Some text" })
{
    smtp.Send(message);
}
MessageBox.Show("Success");

第三次尝试：

try
{
    MailMessage mail = new MailMessage();
    SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com");

    mail.From = new MailAddress("robinx0852@gmail.com");
    mail.To.Add("robinx0852@gmail.com");
    mail.Subject = "Test Mail";
    mail.Body = "This is for testing SMTP mail from GMAIL";

    SmtpServer.Port = 25;
    SmtpServer.Credentials = new System.Net.NetworkCredential("username", "password");
    SmtpServer.EnableSsl = true;

    SmtpServer.Send(mail);
    MessageBox.Show("mail Send");
    MessageBox.Show("Email sent successfully");
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

try
{
    //string s = $"User {edtID} has failed to login";

    MailMessage message = new MailMessage();
    message.To.Add("robinx0852@gmail.com");
    message.Subject = "Employee login failure";
    message.From = new MailAddress("armeepatel@gmail.com");
    message.Body = "Hello";
    SmtpClient smtp = new SmtpClient("smtp.saix.net");
    smtp.Send(message);
    MessageBox.Show("mail Sent");
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

SmtpClient smtp = new SmtpClient();
smtp.Port = 25;
smtp.Credentials = new System.Net.NetworkCredential("username", "password");
smtp.EnableSsl = true;
MailMessage mailMessage = new MailMessage();
mailMessage.To.Add(new MailAddress("mymail@gmail.com", "ME"));
mailMessage.Subject = "Some Subject";
mailMessage.Body = "Test";
smtp.Send(mailMessage);

// string s = $"User {edtID} has failed to login";
MailMessage mail = new MailMessage();
SmtpClient SmtpServer = new SmtpClient();
mail.To.Add("mymail@gmail.com");
mail.From = new MailAddress("hotelfrontdesk@testhotel.com");
mail.Subject = "Employee login failure";
mail.IsBodyHtml = true;
mail.Body = "Hello";
SmtpServer.Host = "smtp.saix.net";
SmtpServer.Port = 25;
SmtpServer.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
try
{

    SmtpServer.Send(mail);
}
catch (Exception ex)
{
    MessageBox.Show("Exception Message: " + ex.Message);
    if (ex.InnerException != null)
        MessageBox.Show("Exception Inner: " + ex.InnerException);

}

var sysLogin = "yourlogin@gmail.com";
var sysPass = "y0urP@ss";
var sysAddress = new MailAddress(sysLogin, "Message from me!");

var receiverAddress = new MailAddress("mymail#gmail.com");

var smtp = new SmtpClient
{
    Host = "smtp.gmail.com",   //gmail example
    Port = 587,
    EnableSsl = false,
    DeliveryMethod = SmtpDeliveryMethod.Network,
    UseDefaultCredentials = false,
    Credentials = new System.Net.NetworkCredential(sysLogin, sysPass)
};


using (var message = new MailMessage(sysAddress, receiverAddress) { Subject = "Some subject", Body = "Some text" })
{
    smtp.Send(message);
}
MessageBox.Show("Success");

第四次尝试：

try
{
    MailMessage mail = new MailMessage();
    SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com");

    mail.From = new MailAddress("robinx0852@gmail.com");
    mail.To.Add("robinx0852@gmail.com");
    mail.Subject = "Test Mail";
    mail.Body = "This is for testing SMTP mail from GMAIL";

    SmtpServer.Port = 25;
    SmtpServer.Credentials = new System.Net.NetworkCredential("username", "password");
    SmtpServer.EnableSsl = true;

    SmtpServer.Send(mail);
    MessageBox.Show("mail Send");
    MessageBox.Show("Email sent successfully");
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

try
{
    //string s = $"User {edtID} has failed to login";

    MailMessage message = new MailMessage();
    message.To.Add("robinx0852@gmail.com");
    message.Subject = "Employee login failure";
    message.From = new MailAddress("armeepatel@gmail.com");
    message.Body = "Hello";
    SmtpClient smtp = new SmtpClient("smtp.saix.net");
    smtp.Send(message);
    MessageBox.Show("mail Sent");
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}

SmtpClient smtp = new SmtpClient();
smtp.Port = 25;
smtp.Credentials = new System.Net.NetworkCredential("username", "password");
smtp.EnableSsl = true;
MailMessage mailMessage = new MailMessage();
mailMessage.To.Add(new MailAddress("mymail@gmail.com", "ME"));
mailMessage.Subject = "Some Subject";
mailMessage.Body = "Test";
smtp.Send(mailMessage);

// string s = $"User {edtID} has failed to login";
MailMessage mail = new MailMessage();
SmtpClient SmtpServer = new SmtpClient();
mail.To.Add("mymail@gmail.com");
mail.From = new MailAddress("hotelfrontdesk@testhotel.com");
mail.Subject = "Employee login failure";
mail.IsBodyHtml = true;
mail.Body = "Hello";
SmtpServer.Host = "smtp.saix.net";
SmtpServer.Port = 25;
SmtpServer.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
try
{

    SmtpServer.Send(mail);
}
catch (Exception ex)
{
    MessageBox.Show("Exception Message: " + ex.Message);
    if (ex.InnerException != null)
        MessageBox.Show("Exception Inner: " + ex.InnerException);

}

var sysLogin = "yourlogin@gmail.com";
var sysPass = "y0urP@ss";
var sysAddress = new MailAddress(sysLogin, "Message from me!");

var receiverAddress = new MailAddress("mymail#gmail.com");

var smtp = new SmtpClient
{
    Host = "smtp.gmail.com",   //gmail example
    Port = 587,
    EnableSsl = false,
    DeliveryMethod = SmtpDeliveryMethod.Network,
    UseDefaultCredentials = false,
    Credentials = new System.Net.NetworkCredential(sysLogin, sysPass)
};


using (var message = new MailMessage(sysAddress, receiverAddress) { Subject = "Some subject", Body = "Some text" })
{
    smtp.Send(message);
}
MessageBox.Show("Success");

---

你试过这个吗？似乎您所有的尝试都使用SSL+25或587+NoSSL。SSL应与端口587连接

var smtpClient = new SmtpClient("smtp.gmail.com")
{
                Port = 587,
                DeliveryMethod = SmtpDeliveryMethod.Network,
                UseDefaultCredentials = false,
                EnableSsl = true,
                Credentials = new NetworkCredential("Myemail@gmail.com", "MyPassword")
};

---

我曾经遇到过一个问题，在使用gmail的stmp设置时，我的电子邮件客户端在发送邮件时会冻结。然后，我必须在Gmail帐户设置中创建一个应用程序密码，并在stmp设置中使用该应用程序密码使我的客户端工作。试试这个，希望它能解决冻结问题

去

选择应用程序[自定义，如果有]、设备[自定义，如果有]，然后单击生成

将生成类似以下内容的密码：kxyo gmnz dais wcau

在stmp设置中使用此应用程序密码，而不是当前使用的密码

---

如果你的代码都被注释掉了，你希望它怎么做？如果您使用的是

SmtpClient

，如何“使用SQL发送电子邮件”？为什么要将

SmtpClient

的实例调用为

SmtpServer

？这似乎是倒退。它全部被注释掉了，因为我尝试了每一个单独的，它运行了所有的东西，但在smtp.Send（message）失败；请看一看：如果您每次尝试都包含异常消息，这将对我们很有帮助。@RandRandom我怀疑这是一个web应用程序，它冻结的行实际上是MessageBox.Show（）行，因为它正在等待有人单击无人能看到的消息框上的“确定”按钮。谢谢Rahul。您能给我一些如何实现的指导吗？这取决于您是否启用了双因素身份验证。如果您确实有2FA，则需要此特定于应用程序的密码。如果您不使用2FA，则需要启用“不太安全的应用程序”，或更新您的C#代码以使用OAuth（并非微不足道）。@Armee我已更新了我的答案，但我的解决方案要求您的帐户启用两步验证。那么只有这样才能起作用。另外，gmail现在对SMTP访问非常挑剔。只有在启用了“不太安全的应用程序”（如果您未使用双因素身份验证）或使用特定于应用程序的密码（如果您使用的是双因素身份验证）的情况下，此功能才有效。