无法测试SmtpClient.TimeOut

Question

我使用的是Visual Studio2010，.NET 4.0，我正在尝试测试SMTPClient.TimeOut属性，并实际让它抛出一个SmtpException。但是，即使当我将TimeOut属性设置为1毫秒时，它仍然会发送电子邮件，看起来不到1毫秒，但我发现有趣的是，当我检查对象时，我可以看到一个名为timedOut的私有成员变量设置为true，这表明它实际上超时了。

​

下面是我的代码：

try
{
            MailMessage emailMsg = new MailMessage(this.EmailFrom, this.EmailTo, this.EmailSubject, msg);
            //SmtpClient emailClient = new SmtpClient(this.EmailServer);
            SmtpClient emailClient = new SmtpClient();
            emailClient.Credentials = new System.Net.NetworkCredential("username", "password");


                emailMsg.IsBodyHtml = true;
                emailClient.Timeout = Properties.Settings.Default.SMTPTimeOut;
                emailClient.Timeout = 1;

                emailClient.Send(emailMsg);
                sendingEmail = true;

            return sendingEmail;
        }
        catch (Exception ex)
        {
              // Handle time out exception here.
         }

有没有人见过或者知道更好的方法来测试它？现在我正在使用gmail的smtp。

Answer 1

为了最终测试它的工作，我在我的本地机器上编写了一个非常简单的TCP服务器控制台应用程序。关于如何做到这一点，我使用了以下教程：http://bit.ly/XoHWPC

通过创建这个控制台应用程序，我能够使用我的服务发送电子邮件并将其指向我的本地计算机(127.0.0.1,25)。TCP服务器控制台应用程序接受了该连接，但之后我再也没有发回响应。

我发送电子邮件的服务如预期的那样成功超时，所以我最终可以验证它是否正常工作。下面是本教程中的TCP Server Console应用程序的一个片段，作为指南。不过，如果你有时间的话，我建议你阅读整个教程。

Program.cs

using System;
using System.Text;
using System.Net.Sockets;
using System.Threading;
using System.Net;

namespace TCPServer
{
    class Program
    {
        static void Main(string[] args)
        {

            Server server = new Server();
        }
    }
}

Server.cs

using System;
using System.Text;
using System.Net.Sockets;
using System.Threading;
using System.Net;

namespace TCPServer
{
    public class Server
    {

        private TcpListener tcpListener;
        private Thread listenThread;

        public Server()
        {
            this.tcpListener = new TcpListener(IPAddress.Any, 25);
            this.listenThread = new Thread(new ThreadStart(ListenForClients));
            this.listenThread.Start();
        }

        private void ListenForClients()
        {
            this.tcpListener.Start();

            while (true)
            {
                //blocks until a client has connected to the server
                TcpClient client = this.tcpListener.AcceptTcpClient();

                //create a thread to handle communication 
                //with connected client
                Thread clientThread = new Thread(new ParameterizedThreadStart(HandleClientComm));
                clientThread.Start(client);
            }
        }

        private void HandleClientComm(object client)
        {
            TcpClient tcpClient = (TcpClient)client;
            NetworkStream clientStream = tcpClient.GetStream();

            byte[] message = new byte[4096];
            int bytesRead;

            while (true)
            {
                bytesRead = 0;

                try
                {
                    //blocks until a client sends a message
                    bytesRead = clientStream.Read(message, 0, 4096);
                }
                catch
                {
                    //a socket error has occured
                    break;
                }

                if (bytesRead == 0)
                {
                    //the client has disconnected from the server
                    break;
                }

                //message has successfully been received
                ASCIIEncoding encoder = new ASCIIEncoding();
                System.Diagnostics.Debug.WriteLine(encoder.GetString(message, 0, bytesRead));
            }

            tcpClient.Close();
        }
    }
}

Answer 2

我相信你可以使用telnet。打开telnet并将该ip用作smtp服务器。它不会连接，因此应该会超时。还没有对此进行测试。

http://technet.microsoft.com/en-us/library/aa995718(v=exchg.65).aspx