求一邮件系统的源代码

这个程序是我自己写的,是通过Soket进行连接的,由于时间仓促所以只写了发送邮件;源程序如下,在这里我只转载了源代码:
using System;
using System.Collections.Generic;
using System.Text;
using
using
using

namespace FTPTest
{
    class MailNotice
    {
        ////////////////////////////////////////////////////////////////////////////////////////////
        //类名：        SendMail
        //功能：        主要实现了邮件的发送功能，是通过SMTP协议实现的
        //基本需求：    需要IO,Net,Net.Sockets命名空间的支持;
        //说明：        邮件发送的内容是固定的，硬编码在了代码中，可根据需要自动修改
        //来源：        [url]http://www.[/url]    学习.NET的殿堂
        ////////////////////////////////////////////////////////////////////////////////////////////
        private IPAddress IPAdd;
        private IPEndPoint IPep;
        private TcpClient client;
        private NetworkStream stream;
        public MailNotice()
        {
            IPAdd = Dns.GetHostEntry("smtp.).AddressList[0];
            IPep = new IPEndPoint(IPAdd, 25);
            client = new TcpClient();
            try
            {
                client.Connect(IPep);
            }
            catch (Exception ep)
            {
                throw new IOException("邮件服务器连接失败：" + ep.Message);
            }
            stream = client.GetStream();
        }
        ~MailNotice()
        {
            if (client.Connected == true)
            {
                client.Close();
            }
        }

        //发送命令
        private void SendCommand(string Command)
        {
            if (stream.CanWrite)
            {
                Byte[] SendByte = Encoding.UTF8.GetBytes(Command);
                try
                {
                    stream.Write(SendByte, 0, SendByte.Length);
                }
                catch (Exception exp)
                {
                    throw new IOException("发送" + Command + "命令出现异常：" + exp.Message);
                }
            }
            else
            {
                throw new IOException("邮件命令发送失败！请检查网络连接。");
            }
        }
        //接受数据
        private string ReceiveEcho()
        {
            if (stream.CanRead)
            {
                Byte[] GetBytes = new Byte[client.ReceiveBufferSize];
                try
                {
                    stream.Read(GetBytes, 0, (int)client.ReceiveBufferSize);
                }
                catch (Exception exp)
                {
                    throw new IOException("接受数据的时候出现了异常：" + exp.Message);
                }
                string Echo = Encoding.UTF8.GetString(GetBytes);
                return Echo;
            }
            else
            {
                throw new IOException("接受数据失败！请检查网络连接。");
            }
        }
        //下面的方法将ascii转换成base64编码
        private string AsciiToBase64(string AsciiMsg)
        {
            byte[] AsciiBytes = new byte[512];
            byte[] Base64Bytes = new byte[512];
            string AsciiMsg1 = null;
            string Base64Msg = null;
            switch (AsciiMsg.Length % 3)
            {
                case 1:
                    {
                        AsciiMsg1 = AsciiMsg + "\0\0";
                        break;
                    }
                case 2:
                    {
                        AsciiMsg1 = AsciiMsg + "\0";
                        break;
                    }
                default:
                    {
                        AsciiMsg1 = AsciiMsg;
                        break;
                    }
            }
            for (int i = 0; i < AsciiMsg1.Length / 3; i++)
            {
                string AsciiMsg2 = AsciiMsg1.Substring(i * 3, 3);
                AsciiBytes = System.Text.Encoding.ASCII.GetBytes(AsciiMsg2);
                System.Security.Cryptography.ToBase64Transform transformer = new System.Security.Cryptography.ToBase64Transform();
                transformer.TransformBlock(AsciiBytes, 0, AsciiBytes.Length, Base64Bytes, 0);
                string str = System.Text.Encoding.ASCII.GetString(Base64Bytes, 0, Base64Bytes.Length);
                str = str.Substring(0, 4);
                Base64Msg += str;
            }
            return Base64Msg;
        }
        //下面函数实现了，邮件的发送。
        public void Send()
        {
            string EmailBody = "";//这里是邮件的内容
            EmailBody += "Hello All,\r\n";
            EmailBody += "http://www.这个是我的主页啊，请多多光顾哦！\r\n";
            string User = "test";//登陆SMTP服务器用户名,比如你自己的邮箱是[email]test@[/email] 密码是test
            string Pass = "test";//登陆密码
            string From = "381616212@发件人地址
            string [] To=new string[2];
            To[0]="381616212@如果有多个收件人，可以这样写
            //To[1] = "dan@收件人地址
            //To[2] = "andy.speed@
            //To[3] = "leopold.li@
            //To[1] = "melinda.xia@
            //To[5] = "leesli@
            string Subject = "FAILURE NOTICE";//邮件的主题
            string Data = EmailBody;//将当前时间作为邮件的正文
            string strCommand = "";
            string Response = "";
            Response = ReceiveEcho();

            //第一次返回信息中如果包含了220就说明服务器连接成功，就可以向服务器发送标识
            if (Response.IndexOf("220") < 0)
            {
                throw new IOException("连接服务器失败：" + Response);
            }
            strCommand = "HELO " + User + "\r\n";
            SendCommand(strCommand);

            //发送标识成功返回信息中就会包含250,发送验证命令
            Response = "";
            Response = ReceiveEcho();
            if (Response.IndexOf("250") < 0)
            {
                throw new IOException("命令" + strCommand + "发送失败！");
            }
            strCommand = "AUTH LOGIN\r\n";
            SendCommand(strCommand);

            //返回信息包含334说明验证命令发送成功，发用户名
            Response = "";
            Response = ReceiveEcho();
            if (Response.IndexOf("334") < 0)
            {
                throw new IOException("命令" + strCommand + "发送失败！");
            }
            strCommand = AsciiToBase64(User) + "\r\n";//用户名和密码必须以base64编码发送
            SendCommand(strCommand);

            //返回信息包含334说明用户名验证成功，发密码
            Response = "";
            Response = ReceiveEcho();
            if (Response.IndexOf("334") < 0)
            {
                throw new IOException("用户名" + strCommand + "验证失败！");
            }
            strCommand = AsciiToBase64(Pass) + "\r\n";//用户名和密码必须以base64编码发送
            SendCommand(strCommand);

            //返回信息包含235说明密码验证成功，发发件地址
            Response = "";
            Response = ReceiveEcho();
            if (Response.IndexOf("235") < 0)
            {
                throw new IOException("密码" + strCommand + "验证失败！");
            }
            strCommand = "MAIL FROM:<" + From + ">\r\n";
            SendCommand(strCommand);

            //返回信息包含250说明mail命令发送成功，发rcpt
            Response = "";
            Response = ReceiveEcho();
            if (Response.IndexOf("250") < 0)
            {
                throw new IOException("命令" + strCommand + "发送失败！");
            }
            for (int i = 0; i < 1; i++)
            {
                strCommand = "RCPT TO:<" + To[i] + ">\r\n";
                SendCommand(strCommand);

                //返回信息包含250说明rcpt to命令发送成功，发data
                Response = "";
                Response = ReceiveEcho();
                if (Response.IndexOf("250") < 0)
                {
                    throw new IOException("命令" + strCommand + "发送失败！");
                }
            }
            strCommand = "DATA\r\n";
            SendCommand(strCommand);

            //返回信息包含354说明Data命令发送成功，发数据
            Response = "";
            Response = ReceiveEcho();
            if (Response.IndexOf("354") < 0)
            {
                throw new IOException("命令" + strCommand + "发送失败！");
            }
            strCommand = "Subject:" + Subject + "\r\n";
            strCommand += "To:" + To + "\r\n";
            strCommand += "Cc:\r\n\r\n" + Data + "\r\n\r\n.\r\n";
            SendCommand(strCommand);

            //返回信息包含250说明邮件发送成功
            Response = "";
            Response = ReceiveEcho();
            if (Response.IndexOf("250") < 0)
            {
                throw new IOException("命令" + strCommand + "发送失败！");
            }
            Console.WriteLine("恭喜！邮件发送成功！");
        }
    }
}

非常感谢,不知道有没有收邮件的呢?
或是收邮件的原理是什么啊?
从网上也找了一些,不是很明确`~~

收藏在
[url]http://www.[/url]
了,
不知作者同意不?不同意的话可以删除!

研究了一段时间了,还是不行,接收不了,我想用IMAIL.或JMAIL来做,怎么把IMAIL或JMAIL导入到.NET命名空间里面呢~~