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
///
/// 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
///
public class SmtpMail
{
private const string ENTER="\r\n";
///
/// 设定语言代码，默认设定为GB2312，如不需要可设置为""
///
private string m_charset="GB2312";
///
/// 服务器交互记录
///
private StringBuilder m_logs = new StringBuilder();
private string m_ErrCode;
///
/// SMTP错误代码哈希表
///
private Hashtable m_ErrCodeHT = new Hashtable();
///
/// SMTP正确代码哈希表
///
private Hashtable m_RightCodeHT = new Hashtable();
///
/// 最多收件人数量
///
private int m_recipientMaxnum = 2;
///
/// 重复时间，以秒为单位
///
private int m_RepeatTime = 120;
///
/// 服务器出错或拒绝后的等待时间,以毫秒为单位
///
private int m_WaitTime = 20000;
///
/// 初始化
///
public SmtpMail()
{
SMTPCodeAdd();
}
#region Properties 定义属性
///
/// 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（lion-a@sohu.com），我将尽快查明原因。
///
public string Logs
{
get
{
return m_logs.ToString();
}
}
///
/// 最多收件人数量
///
public int RecipientMaxNum
{
set
{
m_recipientMaxnum = value;
}
get
{
return m_recipientMaxnum;
}
}
///
/// 设定语言代码，默认设定为GB2312，如不需要可设置为""
///
public string Charset
{
get
{
return this.m_charset;
}
set
{
this.m_charset = value;
}
}
///
/// 重复时间，以秒为单位
///
public int RepeatTime
{
get {return m_RepeatTime;}
set {m_RepeatTime = value;}
}
///
/// 服务器出错或拒绝后的等待时间,以毫秒为单位
///
public int WaitTime
{
get {return m_WaitTime;}
set {m_WaitTime = value > 10000?value:10000;}
}
#endregion
#region Methods 定义方法
///
/// 邮件服务器域名和验证信息
/// 形如："user:pass@www.server.com:25"，也可省略次要信息。如"user:pass@www.server.com"或"www.server.com"
///
/// 输入用户名、密码、邮件服务器域名、端口号
/// 返回邮件服务器域名
/// 返回用户名
/// 返回密码
/// 返回端口号
/// 返回是否需要SMTP验证
///
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;
}
///
/// 添加邮件附件
///
/// 附件绝对路径
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 { 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; } /// /// 添加一组收件人（不超过m_recipientMaxnum个），参数为字符串数组 /// /// 保存有收件人地址的字符串数组（不超过m_recipientMaxnum个） 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 { string recipient = recipients[i].Trim(); if(recipient !=String.Empty && recipient.IndexOf("@") != -1) { recipientList.Add(recipientList.Count,recipients[i]); } } return recipientList; } /// /// 发送邮件方法 /// /// smtp服务器信息，如"username:password@www.smtpServer.com:25"，也可去掉部分次要信息，如"www.smtpServer.com" /// 发件人mail地址 /// 发件人姓名 /// 收件人地址列表 /// 收件人姓名 /// 是否HTML邮件 /// 邮件主题 /// 邮件正文 /// 邮件附件列表 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 /// /// SMTP回应代码哈希表 /// 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 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 m_RightCodeHT.Add("354","开始邮件输入，以 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"); } /// /// 将字符串编码为Base64字符串 /// /// 要编码的字符串 private string Base64Encode(string str) { byte[] barray; barray=Encoding.Default.GetBytes(str); return Convert.ToBase64String(barray); } /// /// 将Base64字符串解码为普通字符串 /// /// 要解码的字符串 private string Base64Decode(string str) { byte[] barray; barray=Convert.FromBase64String(str); return Encoding.Default.GetString(barray); } /// /// 得到上传附件的文件流 /// /// 附件的绝对路径 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; } /// /// 发送SMTP命令 /// 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; } /// /// 接收SMTP服务器回应 /// 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; } } /// /// 与服务器交互，发送一条命令并接收回应。 /// /// 一个要发送的命令 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; } } /// /// 与服务器交互，发送一组命令并接收回应。 /// private bool Dialog(string[] str,NetworkStream _NetworkStream) { for(int i=0;i { if(!Dialog(str[i],_NetworkStream)) { return false; } } return true; } /// /// SendEmail /// /// 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 { 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 { 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 { 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 /* /// /// 添加一个密件收件人 /// /// 收件人地址 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; } } /// /// 添加一组密件收件人（不超过10个），参数为字符串数组 /// /// 保存有收件人地址的字符串数组（不超过10个） public bool AddRecipientBCC(string[] str) { for(int i=0;i { if(!AddRecipientBCC(str[i])) { return false; } } return true; } */ #endregion } /// /// 邮件发送优先级 /// public enum Priority { High, Normal, Low } #endregion }