c#+email发送系统

以下是转自:http://www.cnblogs.com/chjx42/articles/463830.html

email发送系统(c#+基于smtp认证)
http://www.lionsky.net/MyWebsite/article/list.aspx?id=430

 

的改版
        在为公司写通知服务时，从网上找到了以上地址，非常感谢原作者创造性的劳动。改写的目的是为了适应作为服务运行的要求：
1、适应多线程的要求，发送邮件服务可在后台运行，将与SMTP服务器的连接视为独占资源。
2、适应稳定性的要求，不再以简单地抛出异常来处理错误，在出现异常后等待一定时间间隔后重试，重试一段时间间隔后若还时发不出去，则认为是SMTP出错，返回发送邮件不成功的标识。
3、精简属性、方法，与邮件相关的信息不再作为属性，而是作为send的参数传入；只公布了一个无重载的send方法。以此类为基类，另写通知服务要求的接口方法。
以下是改写后的代码：
using System;
using System.Text;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Collections;
using System.Threading;

namespace Deep.SendEmail
{
 #region AspNetPager Server Control

 /// <summary>
 /// 邮件可以通过 Microsoft Windows 2000 中内置的 SMTP 邮件服务或任意 SMTP 服务器来传送
 /// </summary>
 public class SmtpMail
 {

  private const string  ENTER="\r\n";

  /// <summary>
  /// 设定语言代码，默认设定为GB2312，如不需要可设置为""
  /// </summary>
  private string m_charset="GB2312";
  
  /// <summary>
  /// 服务器交互记录
  /// </summary>
  private StringBuilder m_logs = new StringBuilder();

  private string m_ErrCode;

  /// <summary>
  /// SMTP错误代码哈希表
  /// </summary>
  private Hashtable m_ErrCodeHT = new Hashtable();

  /// <summary>
  /// SMTP正确代码哈希表
  /// </summary>
  private Hashtable m_RightCodeHT = new Hashtable();

  
  /// <summary>
  /// 最多收件人数量
  /// </summary>
  private int m_recipientMaxnum = 2;

  /// <summary>
  /// 重复时间，以秒为单位
  /// </summary>
  private int m_RepeatTime = 120;

  /// <summary>
  /// 服务器出错或拒绝后的等待时间,以毫秒为单位
  /// </summary>
  private int m_WaitTime = 20000;

  /// <summary>
  /// 初始化 <see cref="Lion.Web.Mail.SmtpMail"/> 类的新实例
  /// </summary>
  public SmtpMail()
  {
   SMTPCodeAdd();
  }

  #region Properties 定义属性
  /// <summary>
  /// 服务器交互记录，如发现本组件不能使用的SMTP服务器，请将出错时的Logs发给我（[email protected]），我将尽快查明原因。
  /// </summary>
  public string Logs
  {
   get
   {
    return m_logs.ToString();
   }
  }

  /// <summary>
  /// 最多收件人数量
  /// </summary>
  public int RecipientMaxNum
  {
   set
   {
    m_recipientMaxnum = value;
   }
   get
   {
    return m_recipientMaxnum;
   }
  }

  /// <summary>
  /// 设定语言代码，默认设定为GB2312，如不需要可设置为""
  /// </summary>
  public string Charset
  {
   get
   {
    return this.m_charset;
   }
   set
   {
    this.m_charset = value;
   }
  }

  
  /// <summary>
  /// 重复时间，以秒为单位
  /// </summary>
  public int RepeatTime
  {
   get {return m_RepeatTime;}
   set {m_RepeatTime = value;}

  }

  /// <summary>
  /// 服务器出错或拒绝后的等待时间,以毫秒为单位
  /// </summary>
  public int WaitTime
  {
   get {return m_WaitTime;}
   set {m_WaitTime = value > 10000?value:10000;}
  }

  #endregion

  #region Methods 定义方法

  /// <summary>
  /// 邮件服务器域名和验证信息
  /// 形如："user:[email protected]:25"，也可省略次要信息。如"user:[email protected]"或"www.server.com"
  /// </summary>
  /// <param name="mailDomain">输入用户名、密码、邮件服务器域名、端口号</param>
  /// <param name="mailServer">返回邮件服务器域名</param>
  /// <param name="mailServerUserName">返回用户名</param>
  /// <param name="password">返回密码</param>
  /// <param name="mailserverport">返回端口号</param>
  /// <param name="needSmtp">返回是否需要SMTP验证</param>
  /// <returns></returns>
  private bool SetMailDomain(string mailDomain,out string mailServer,out string mailServerUserName,out string password,
   out int mailserverport,out bool needSmtp)
  {
   bool isRight = false;
   //为输出变量赋初值
   mailServer = string.Empty;
   mailServerUserName = String.Empty;
   password = String.Empty;
   mailserverport = 25;
   needSmtp = false;

   mailserver = mailDomain.Trim();
   int tempint;
   if( mailServer != "" )
   {
    tempint = mailServer.IndexOf("@");
    isRight = true;
    if(tempint!=-1)
    {
     string str = mailServer.Substring(0,tempint);
     mailServerUserName = str.Substring(0,str.IndexOf(":"));
     password = str.Substring(str.IndexOf(":")+1,str.Length-str.IndexOf(":")-1);
     needSmtp = !(password==string.Empty);
     mailServer = mailDomain.Substring(tempint+1,mailDomain.Length-tempint-1);
    }

    tempint = mailServer.IndexOf(":");
    if(tempint != -1)
    {
     mailserverport = System.Convert.ToInt32(mailServer.Substring(tempint+1,mailServer.Length-tempint-1));
     mailServer = mailServer.Substring(0,tempint);
    }
   }

   return isRight;
  }

  /// <summary>
  /// 添加邮件附件
  /// </summary>
  /// <param name="filePath">附件绝对路径</param>
  private  IList AddAttachment(params string[] filePath)
  {
   if(filePath == null || filePath.Length == 0)
   {
    return null;
   }
   IList m_Attachments = new System.Collections.ArrayList();// 邮件附件列表
   for(int i=0;i<filePath.Length;i++)
   {
    if(File.Exists(filePath[i]))
    {
     m_Attachments.Add(filePath[i]);
    }
    else
    {
     m_logs.Append("错误：没找到文件名为"+filePath[i]+"的附件文件！"+ENTER);
    }
   }
   return m_Attachments;
  }
  
  /// <summary>
  /// 添加一组收件人（不超过m_recipientMaxnum个），参数为字符串数组
  /// </summary>
  /// <param name="recipients">保存有收件人地址的字符串数组（不超过m_recipientMaxnum个）</param> 
  private Hashtable AddRecipient(params string[] recipients)
  {
   if(recipients==null || recipients.Length == 0)
   {
    return null;
   }
   Hashtable recipientList=new Hashtable();// 收件人列表

   for(int i=0;i<recipients.Length;i++)
   {
    string recipient = recipients[i].Trim();
    if(recipient !=String.Empty && recipient.IndexOf("@") != -1)
    {
     recipientList.Add(recipientList.Count,recipients[i]);
    }
   }
   return recipientList;
  }

  /// <summary>
  /// 发送邮件方法
  /// </summary>
  /// <param name="smtpServer">smtp服务器信息，如"username:[email protected]:25"，也可去掉部分次要信息，如">
  /// <param name="from">发件人mail地址</param>
  /// <param name="fromname">发件人姓名</param>
  /// <param name="to">收件人地址列表</param>
  /// <param name="toname">收件人姓名</param>
  /// <param name="html">是否HTML邮件</param>
  /// <param name="subject">邮件主题</param>
  /// <param name="body">邮件正文</param>
  ///  <param name="filePath">邮件附件列表</param>
  public bool Send(string smtpServer,string from,string fromName,string[] recipientADD,string recipientName,bool isHtml,string subject,Priority priority,  string body,string[] filePath)
  {
   //如果收件人多于服务器可同时发送的最大值，则分多次发送
   if(recipientADD.Length > RecipientMaxNum)
   {
    string[] recipientADD1  = new string[RecipientMaxNum];
    string[] recipientADD2  = new string[recipientADD.Length - RecipientMaxNum];
    for(int i = 0;i < recipientADD.Length; i++)
    {
     if(i < RecipientMaxNum)
     {
      recipientADD1[i] = recipientADD[i];
     }
     else
     {
      recipientADD2[i - RecipientMaxNum] = recipientADD[i];
     }
    }
    return Send(smtpServer,from,fromName,recipientADD1,recipientName,isHtml,subject,priority,  body,filePath)
     &&
     Send(smtpServer,from,fromName,recipientADD2,recipientName,isHtml,subject,priority,  body,filePath);
   }

   if(m_logs.length > 2048)
   {
    m_logs.Remove(0,m_logs.Length);
   }

   string mailServer="";// 邮件服务器域名
   int mailserverport=25;// 邮件服务器端口号
   string userName="";// SMTP认证时使用的用户名
   string password="";// SMTP认证时使用的密码
   bool needSmtp=false;// 是否需要SMTP验证
   SetMailDomain(smtpServer,out mailServer,out userName,out password,
    out mailserverport,out needSmtp);
   if(mailServer.Trim()=="")
   {
    m_logs.Append("必须指定SMTP服务器"+ENTER);
    return false;
   }
   IList attachments = AddAttachment(filePath);// 邮件附件列表
   Hashtable recipients = AddRecipient(recipientADD);// 收件人列表
   if(recipients == null || recipients.Count == 0 )
   {
    m_logs.Append("必须指定收件人"+ENTER);
    return false;
   }
   if(recipients.Count > RecipientMaxNum)
   {
    m_logs.Append("一次发送的收件人太多"+ENTER);
    return false;
   }
   bool isSuccessful = false;
   lock(this)
   {
    TcpClient tcpClientObject = null;// TcpClient对象，用于连接服务器
    NetworkStream networkStreamObject = null;// NetworkStream对象
    DateTime dateTimeBegin = DateTime.Now;
    int useTime = 0;
    while(! ( useTime > RepeatTime || isSuccessful))
    {
     try
     {
      tcpClientObject=new TcpClient(mailServer,mailserverport);
      networkStreamObject = tcpClientObject.GetStream();
      isSuccessful =SendEmail(networkStreamObject,needSmtp,mailServer,userName,password,recipients,from,
       fromName,recipientName,subject,priority.ToString(),attachments, isHtml, body);
     }
     catch(Exception e)
     {
      m_logs.Append("错误："+e.Message+ENTER);
     }
     finally
     {
      if(networkStreamObject!=null)networkStreamObject.Close();
      if(tcpClientObject!=null)tcpClientObject.Close();
      if(!isSuccessful)
      {
       string n = Thread.CurrentThread.Name;
       Thread.Sleep(WaitTime);
      }
      useTime = ((TimeSpan)(DateTime.Now - dateTimeBegin)).Seconds;
     }
    }
   }
   return isSuccessful;
  }
 

  #endregion

  #region Private Helper Functions

  /// <summary>
  /// SMTP回应代码哈希表
  /// </summary>
  private void SMTPCodeAdd()
  {
   m_ErrCodeHT.Add("500","邮箱地址错误");
   m_ErrCodeHT.Add("501","参数格式错误");
   m_ErrCodeHT.Add("502","命令不可实现");
   m_ErrCodeHT.Add("503","服务器需要SMTP验证");
   m_ErrCodeHT.Add("504","命令参数不可实现");
   m_ErrCodeHT.Add("421","服务未就绪，关闭传输信道");
   m_ErrCodeHT.Add("450","要求的邮件操作未完成，邮箱不可用（例如，邮箱忙）");
   m_ErrCodeHT.Add("550","要求的邮件操作未完成，邮箱不可用（例如，邮箱未找到，或不可访问）");
   m_ErrCodeHT.Add("451","放弃要求的操作；处理过程中出错");
   m_ErrCodeHT.Add("551","用户非本地，请尝试<forward-path>");
   m_ErrCodeHT.Add("452","系统存储不足，要求的操作未执行");
   m_ErrCodeHT.Add("552","过量的存储分配，要求的操作未执行");
   m_ErrCodeHT.Add("553","邮箱名不可用，要求的操作未执行（例如邮箱格式错误）");
   m_ErrCodeHT.Add("432","需要一个密码转换");
   m_ErrCodeHT.Add("534","认证机制过于简单");
   m_ErrCodeHT.Add("538","当前请求的认证机制需要加密");
   m_ErrCodeHT.Add("454","临时认证失败");
   m_ErrCodeHT.Add("530","需要认证");

   m_rightcodeht.add("220","服务就绪");
   m_RightCodeHT.Add("250","要求的邮件操作完成");
   m_RightCodeHT.Add("251","用户非本地，将转发向<forward-path>");
   m_RightCodeHT.Add("354","开始邮件输入，以<enter>.<enter>结束");
   m_RightCodeHT.Add("221","服务关闭传输信道");
   m_RightCodeHT.Add("334","服务器响应验证Base64字符串");
   m_RightCodeHT.Add("235","验证成功");
  }

  /// <summary>
  /// 将字符串编码为Base64字符串
  /// </summary>
  /// <param name="str">要编码的字符串</param>
  private string Base64Encode(string str)
  {
   byte[] barray;
   barray=Encoding.Default.GetBytes(str);
   return Convert.ToBase64String(barray);
  }

  /// <summary>
  /// 将Base64字符串解码为普通字符串
  /// </summary>
  /// <param name="str">要解码的字符串</param>
  private string Base64Decode(string str)
  {
   byte[] barray;
   barray=Convert.FromBase64String(str);
   return Encoding.Default.GetString(barray);
  }

  
  /// <summary>
  /// 得到上传附件的文件流
  /// </summary>
  /// <param name="filePath">附件的绝对路径</param>
  private string GetStream(string filePath)
  {
   byte[] by = null;
   System.IO.FileStream FileStr = null;
   string streamString = "";
   try
   {
    //建立文件流对象
    FileStr=new System.IO.FileStream(filePath,System.IO.FileMode.Open);
    by=new byte[System.Convert.ToInt32(FileStr.Length)];
    FileStr.Read(by,0,by.Length);
    streamString = System.Convert.ToBase64String(by);
   }
   catch(Exception ex)
   {
    //写错误日志
    m_logs.Append("错误："+ex.Message+ENTER);
   }
   finally
   {
    if(FileStr != null)
    {
     FileStr.Close();
    }
   }

   return streamString;
  }

  /// <summary>
  /// 发送SMTP命令
  /// </summary> 
  private bool SendCommand(string str,NetworkStream _NetworkStreamObject)
  {
   byte[]  WriteBuffer;
   if(str==null||str.Trim()==String.Empty)
   {
    return true;
   }
   m_logs.Append(str+ENTER);
   WriteBuffer = Encoding.Default.GetBytes(str);
   try
   {
    _NetworkStreamObject.Write(WriteBuffer,0,WriteBuffer.Length);
   }
   catch(Exception ex)
   {
    //写日志
    m_logs.Append("错误："+ex.Message+ENTER);
    return false;
   }
   return true;
  }

  /// <summary>
  /// 接收SMTP服务器回应
  /// </summary>
  private string RecvResponse(NetworkStream _NetworkStreamObject)
  {
   int StreamSize = 0;
   string ReturnValue = String.Empty;
   byte[]  ReadBuffer = new byte[1024] ;
   try
   {
    StreamSize = _NetworkStreamObject.Read(ReadBuffer,0,ReadBuffer.Length);
   }
   catch(Exception ex)
   {
    //写日志
    m_logs.Append("错误："+ex.Message+ENTER);
    m_ErrCode = ex.Message;
    return "false";
   }

   if (StreamSize==0)
   {
    return ReturnValue ;
   }
   else
   {
    ReturnValue = Encoding.Default.GetString(ReadBuffer).Substring(0,StreamSize);
    m_logs.Append(ReturnValue+ENTER);
    return  ReturnValue;
   }
  }

  /// <summary>
  /// 与服务器交互，发送一条命令并接收回应。
  /// </summary>
  /// <param name="str">一个要发送的命令</param>
  private bool Dialog(string str,NetworkStream _NetworkStream)
  {
   if(str==null||str.Trim()=="")
   {
    return true;
   }
   if(SendCommand(str,_NetworkStream))
   {
    string RR=RecvResponse(_NetworkStream);
    if(RR=="false")
    {
     return false;
    }
    string RRCode=RR.Substring(0,3);
    if(m_RightCodeHT[RRCode]!=null)
    {
     return true;
    }
    else
    {
     m_ErrCode = RRCode;
     return false;
    }
   }
   else
   {
    return false;
   }

  }

  /// <summary>
  /// 与服务器交互，发送一组命令并接收回应。
  /// </summary>

  private bool Dialog(string[] str,NetworkStream _NetworkStream)
  {
   for(int i=0;i<str.Length;i++)
   {
    if(!Dialog(str[i],_NetworkStream))
    {
     return false;
    }
   }

   return true;
  }

  
  /// <summary>
  /// SendEmail
  /// </summary>
  /// <returns></returns>
  private bool SendEmail(NetworkStream _NetworkStream,bool needSmtp,string mailServer,string userName,string password,Hashtable recipients,string from,
   string fromName,string recipientName,string subject,string priority,IList attachments,bool isHtml,
   string body)
  {
   //验证网络连接是否正确
   if(m_RightCodeHT[RecvResponse(_NetworkStream).Substring(0,3)]==null)
   {
    return false;
   }

   string[] SendBuffer;
   string SendBufferstr;
   StringBuilder SendBufferstrBuilder = new StringBuilder();

   //进行smtp验证
   if(needSmtp)
   {
    SendBuffer=new String[4];
    SendBuffer[0]="EHLO " + mailServer + ENTER;
    SendBuffer[1]="AUTH LOGIN" + ENTER;
    SendBuffer[2]=Base64Encode(userName) + ENTER;
    SendBuffer[3]=Base64Encode(password) + ENTER;
    if(!Dialog(SendBuffer,_NetworkStream))
    {
     return false;
    }
   }
   else
   {
    SendBufferstr="HELO " + mailServer + ENTER;
    if(!Dialog(SendBufferstr,_NetworkStream))
     return false;
   }

   //
   SendBufferstr="MAIL FROM:<" + from + ">" + ENTER;
   if(!Dialog(SendBufferstr,_NetworkStream))
    return false;

   //
   SendBuffer=new string[m_recipientMaxnum];
   for(int i=0;i<recipients.Count;i++)
   {
    SendBuffer[i]="RCPT TO:<" + recipients[i].ToString() +">" + ENTER;

   }

   if(!dialog(sendbuffer,_networkstream))
    return false;
   SendBufferstr="DATA" + ENTER;
   if(!Dialog(SendBufferstr,_NetworkStream))
    return false;

   sendbufferstrbuilder.append("from:" + fromName + "<" + from +">" +ENTER);
     
   SendBufferstrBuilder.Append("To:=?"+Charset.ToUpper()+"?B?"+Base64Encode(recipientName)+"?="+"<"+recipients[0]+">"+ENTER);
   
   SendBufferstrBuilder.Append("CC:");
   for(int i=0;i<recipients.Count;i++)
   {
    SendBufferstrBuilder.Append(recipients[i].ToString() + "<" + recipients[i].ToString() +">,");
   }
   SendBufferstrBuilder.Append(ENTER);

   sendbufferstrbuilder.append(((subject==string.empty || subject==null)?"Subject:":((Charset=="")?("Subject:" + subject):("Subject:" + "=?" + Charset.ToUpper() + "?B?" + Base64Encode(subject) +"?="))) + ENTER);
   SendBufferstrBuilder.Append("X-Priority:" + priority + ENTER);
   SendBufferstrBuilder.Append("X-MSMail-Priority:" + priority + ENTER);
   SendBufferstrBuilder.Append("Importance:" + priority + ENTER);
   SendBufferstrBuilder.Append("X-Mailer: Lion.Web.Mail.SmtpMail Pubclass [cn]" + ENTER);
   SendBufferstrBuilder.Append("MIME-Version: 1.0" + ENTER);

   if(attachments != null && attachments.Count!=0)
   {
    SendBufferstrBuilder.Append("Content-Type: multipart/mixed;" + ENTER);
    SendBufferstrBuilder.Append(" boundary=\"====="+(isHtml?"001_Dragon520636771063_":"001_Dragon303406132050_")+"=====\""+ENTER+ENTER);
   }

   if(ishtml)
   {
    if(attachments != null && attachments.Count==0)
    {
     SendBufferstrBuilder.Append("Content-Type: multipart/alternative;"+ENTER);//内容格式和分隔符
     SendBufferstrBuilder.Append(" boundary=\"=====003_Dragon520636771063_=====\""+ENTER+ENTER);

     sendbufferstrbuilder.append("this is a multi-part message in MIME format."+ENTER+ENTER);
    }
    else
    {
     SendBufferstrBuilder.Append("This is a multi-part message in MIME format."+ENTER+ENTER);
     SendBufferstrBuilder.Append("--=====001_Dragon520636771063_====="+ENTER);
     SendBufferstrBuilder.Append("Content-Type: multipart/alternative;"+ENTER);//内容格式和分隔符
     SendBufferstrBuilder.Append(" boundary=\"=====003_Dragon520636771063_=====\""+ENTER+ENTER);     
    }
    SendBufferstrBuilder.Append("--=====003_Dragon520636771063_====="+ENTER);
    SendBufferstrBuilder.Append("Content-Type: text/plain;"+ ENTER);
    SendBufferstrBuilder.Append(((Charset=="")?(" charset=\"iso-8859-1\""):(" charset=\"" + Charset.ToLower() + "\"")) + ENTER);
    SendBufferstrBuilder.Append("Content-Transfer-Encoding: base64" + ENTER + ENTER);
    SendBufferstrBuilder.Append(Base64Encode("邮件内容为HTML格式，请选择HTML方式查看") + ENTER + ENTER);

    sendbufferstrbuilder.append("--=====003_dragon520636771063_====="+enter);

    

    sendbufferstrbuilder.append("content-type: text/html;" + ENTER);
    SendBufferstrBuilder.Append(((Charset=="")?(" charset=\"iso-8859-1\""):(" charset=\"" + Charset.ToLower() + "\"")) + ENTER);
    SendBufferstrBuilder.Append("Content-Transfer-Encoding: base64" + ENTER + ENTER);
    SendBufferstrBuilder.Append(Base64Encode(body) + ENTER + ENTER);
    SendBufferstrBuilder.Append("--=====003_Dragon520636771063_=====--"+ENTER);
   }
   else
   {
    if(attachments != null && attachments.Count!=0)
    {
     SendBufferstrBuilder.Append("--=====001_Dragon303406132050_====="+ENTER);
    }
    SendBufferstrBuilder.Append("Content-Type: text/plain;" + ENTER);
    SendBufferstrBuilder.Append(((Charset=="")?(" charset=\"iso-8859-1\""):(" charset=\"" + Charset.ToLower() + "\"")) + ENTER);
    SendBufferstrBuilder.Append("Content-Transfer-Encoding: base64" + ENTER + ENTER);
    SendBufferstrBuilder.Append(Base64Encode(body) + ENTER);
   }
   
   //SendBufferstr += "Content-Transfer-Encoding: base64"+ENTER;
   if(attachments != null && attachments.Count!=0)
   {
    for(int i=0;i<attachments.Count;i++)
    {
     string filepath = (string)attachments[i];
     SendBufferstrBuilder.Append("--====="+ (isHtml?"001_Dragon520636771063_":"001_Dragon303406132050_") +"====="+ENTER);
     //SendBufferstr += "Content-Type: application/octet-stream"+ENTER;
     SendBufferstrBuilder.Append("Content-Type: text/plain;"+ENTER);
     SendBufferstrBuilder.Append(" name=\"=?"+Charset.ToUpper()+"?B?"+Base64Encode(filepath.Substring(filepath.LastIndexOf("\\")+1))+"?=\""+ENTER);
     SendBufferstrBuilder.Append("Content-Transfer-Encoding: base64"+ENTER);
     SendBufferstrBuilder.Append("Content-Disposition: attachment;"+ENTER);
     SendBufferstrBuilder.Append(" filename=\"=?"+Charset.ToUpper()+"?B?"+Base64Encode(filepath.Substring(filepath.LastIndexOf("\\")+1))+"?=\""+ENTER+ENTER);
     SendBufferstrBuilder.Append(GetStream(filepath)+ENTER+ENTER);
    }
    SendBufferstrBuilder.Append("--====="+ (isHtml?"001_Dragon520636771063_":"001_Dragon303406132050_") +"=====--"+ENTER+ENTER);
   }
   SendBufferstrBuilder.Append(ENTER + "." + ENTER);
   SendBufferstr = SendBufferstrBuilder.ToString();

   if(!dialog(sendbufferstr,_networkstream))
    return false;

   SendBufferstr="QUIT" + ENTER;
   if(!Dialog(SendBufferstr,_NetworkStream))
    return false;

   return true;
  }

  #endregion

  #region
  /*
  /// <summary>
  /// 添加一个密件收件人
  /// </summary>
  /// <param name="str">收件人地址</param>
  public bool AddRecipientBCC(string str)
  {
   if(str==null||str.Trim()=="")
    return true;
   if(RecipientBCCNum<10)
   {
    RecipientBCC.Add(RecipientBCCNum,str);
    RecipientBCCNum++;
    return true;
   }
   else
   {
    m_logs.Append("错误：收件人过多");
    return false;
   }
  }

  /// <summary>
  /// 添加一组密件收件人（不超过10个），参数为字符串数组
  /// </summary> 
  /// <param name="str">保存有收件人地址的字符串数组（不超过10个）</param>
  public bool AddRecipientBCC(string[] str)
  {
   for(int i=0;i<str.Length;i++)
   {
    if(!AddRecipientBCC(str[i]))
    {
     return false;
    }
   }
   return true;
  }

  */   
  #endregion 
 }

 /// <summary>
 /// 邮件发送优先级
 /// </summary>
 public enum Priority
 {
  High,
  Normal,
  Low
 }

 #endregion

}