POP3 邮件接收 出现乱码了，希望哪位能帮忙看下啥问题！帮我改下，谢谢

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.IO;
using MailReceiver;

namespace MailReceiver
{
    public partial class Form1 : Form
    {
        public TcpClient Server;
        public NetworkStream NetStrm;
        public StreamReader RdStrm;
        public string Data;
        public byte[] szData;
        public string CRLF = "/r/n";

        public Form1()
        {
            InitializeComponent();
        }

        private void Connect_Click(object sender, EventArgs e)
        {
            //将光标置为等待状态
            Cursor cr = Cursor.Current;
            Cursor.Current = Cursors.WaitCursor;

            //用110端口新建POP3服务器连接
            Server = new TcpClient(PopServer.Text, 110);
            Sta