高效的Esmtp,带验证，用Socket编写

using System;

using System.Net;

using System.Net.Sockets;

using System.Collections;

using System.Configuration;

using System.Text;

using System.Xml;

using System.IO;

using System.Web;

using System.Web.Mail;

namespace mail

{

/// <summary>

/// Class1 的摘要说明。

/// </summary>

public class mSendMail

{

private TcpClient tcpClt;

private NetworkStream networkStm;

private Hashtable rightCodeHT = new Hashtable();

private string smtpServerName;

private int smtpServerPort;

private string userName;

private string password;

private string to;

private string from;

private string fromName;

private string charset;

private string recipientName;

private string subject;

private string body;