pop3 读取邮件

Cursor cr = Cursor.Current;
			Cursor.Current = Cursors.WaitCursor;
			Server = new TcpClient( POPServ.Text ,110);
			//建立和POP3的TCP连接
			string RecString;
			try
			{
				NetStrm = Server.GetStream();
				//获取客户机和服务器会话的数据流
				RdStrm= new StreamReader(Server.GetStream(),Encoding.GetEncoding("gb2312"));
				RecString = RdStrm.ReadLine();
				Data = "USER "  User.Text CRLF;				
				//定义传送帐户名称的命令
				szData = System.Text.Encoding.GetEncoding("gb2312").GetBytes(Data.ToCharArray());
				NetStrm.Write(szData,0,szData.Length);
				//向服务器传送帐户
				RecString = RdStrm.ReadLine();
				//接收服务器反馈数据
				Data = "PASS "  Passw.Text CRLF;				
				//定义帐户对应的口令的命令
				szData = System.Text.Encoding.GetEncoding("gb2312").GetBytes(Data.ToCharArray());
				NetStrm.Write(szData,0,szData.Length);
				//向服务器传送帐户的口令
				RecString = RdStrm.ReadLine();
				//接收服务器反馈数据
				Data = "STAT" CRLF;				
				//定义获取邮箱中邮件数目和占用空间的命令
				szData = System.Text.Encoding.GetEncoding("gb2312").GetBytes(Data.ToCharArray());
				NetStrm.Write(szData,0,szData.Length);
				//传送胡琴邮箱中邮件数目和占用空间的命令
				RecString = RdStrm.ReadLine();
				//接收服务器反馈的数据
				String[] Num = RecString.Split(" ".ToCharArray());
				if (Int32.Parse(Num[1]) > 0)
				{
                    lbl1.Text = "邮件数目："   Num[1]   ",所占空间："   Num[2]   "字节";
					numericUpDown1.Maximum = Int32.Parse (Num[1]);
					ConnectBtn.Enabled = false;
					DisconnectBtn.Enabled = true;
					RetrieveBtn.Enabled = true;
				}
				else
					MessageBox.Show("邮箱中没有邮件！");
				//以上是解析STAT命令后服务器反馈的数据，并通过状态条显示出来
			}
			catch(InvalidOperationException err)
			{
                lbl1.Text = "错误: "   err.ToString();
			}
			Cursor.Current = cr;