unable to send email via gmail

Question

I am trying to send via gmail in c# using stmp.gmail.com but keep on getting authentication 5.5.1 issue under port 587 and under port 465 i get an operation timed out.

Please see my code and let me know how and where I am going wrong and how to resolve.

thanks

private void SendMessage(object sender, RoutedEventArgs e)
    {

        var connected = ConnectedToInternet();
        if (!connected) return;

        var Client = new SmtpClient
        {
            Host = "smtp.gmail.com",
            Port = 465,
            EnableSsl = true,
            DeliveryMethod = SmtpDeliveryMethod.Network,
            Credentials = new NetworkCredential(txtUserName.Text, txtPassword.Password),
            Timeout = 20000
        };

        var m = new MailMessage { Subject = txtSubject.Text, IsBodyHtml = true, Body = txtMessage.Text };
        foreach (var email in LbEmailAddresses.Items)
        {
            try
            {
                m.To.Add(new MailAddress(email.ToString().Trim()));
                m.From = new MailAddress(txtUserName.Text);
                Client.Send(m);
                m.To.Clear();
                Success.Add(email.ToString());
            }
            catch (SmtpException esException)
            {
                Errors.Add("Error sending to " + email + " " + esException.Message);
            }
            catch (Exception ex)
            {
                Errors.Add("Error sending to " + email + " " + ex.Message);

            }

        }
        var message = new StringBuilder();
        message.AppendLine(Success.Count() + " Sent Successfully");
        message.AppendLine(Errors.Count() + " Errors Click See Error Log for more information");
        if (CustomMessageBox.ShowYesNo(message.ToString(),
            "Result",
            "Ok",
            "View Log") != MessageBoxResult.No) return;
        using (var sw = new StreamWriter("log.txt"))
        {
            foreach (var error in Errors)
            {
                sw.WriteLine(error);
            }
            Process.Start("log.txt");
        }
    }

Answer 1

我上面关于Google电子邮件的评论...如果您要通过C＃或其他Google批准的应用发送邮件，则需要降低帐户的安全性。