首先引入j2ee的包路径到classpath,已经安装jbuilder的可以在它的安装路径lib目录下找
到mail.jar,activation.jar,将这两个包加入系统的环境变量,那么即使不用jbuilder开发的话也可以
使用了.

        程序:

import java.io.*;
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;

/**
 * <p>title: 简易mailbean</p>
 * <p>description: 提供简便的mail发送功能（/p>
 * <p>copyright: copyright (c) 2003</p>
 * @version 1.0
 */

class extendstring {
  public extendstring() {
  }
  /**
   去掉字符串两端的空白字符,并将字符串转化为中国的标准字符gb2312的字符串.
   */
  public string cs(string str) { //去掉字符串2端的空白字符
      try {
          if (str == null)
              return "";
          str = str.trim();
          if (str == null)
              return "";
          str = new string(str.getbytes("8859_1"), "gbk");
      }
      catch (exception e) {
          system.out.println(e);
      }
      return str;
  }

}

public class sendmail
{
    private string errmsg = "";
    private extendstring exstr = new extendstring();

    private string sender = "";//发件人地址
    private string smtphost = "";//邮件发送服务器（smtp）
    private string user = ""; //登录用户名
    private string password = "";//登录密码

    private string subject = "";//mail主题

    public sendmail()
    {
        this.setpropertiesattri();
    }

    private void setpropertiesattri()
    {
        try
        {
            inputstream is = getclass().getresourceasstream("mailserver.properties");
            properties prop = new properties();
            prop.load(is);

            this.setsmtphost(prop.get("smtphost").tostring());
            this.setuser(prop.get("user").tostring());
            this.setpassword(prop.get("password").tostring());
            this.setsender(prop.get("sender").tostring());
            this.setsubject(exstr.cs(prop.get("subject").tostring()));
        }
        catch(exception ex)
        {
            system.err.println("ex1 in sendmail.java:"+ex.tostring());
        }
    }
    /** 设置发件人地址 */

    public void setsender(string sender)
    {
        this.sender = sender;
    }

    public string getsender()
    {
        return sender;
    }

    /** 设置邮件发送服务器（smtp） */
    public void setsmtphost(string smtphost) {this.smtphost = smtphost;}
    public string getsmtphost() {return smtphost;}

    /** 设置登录用户名 */
    public void setuser(string user)
    {
        this.user = user;
    }
    public string getuser()
    {
        return user;
    }

    /** 设置登录密码 */
    public void setpassword(string password)
    {
        this.password = password;
    }
    public string getpassword()
    {
        return password;
    }

    /** 设置mail主题 */
    public void setsubject(string subject)
    {
        this.subject = subject;
    }
    public string getsubject()
    {
        return subject;
    }

    /**
     * 使用smtp发送邮件 主程序
     * @throws messagingexception mail发送失败
     */
    public void smtp(string receiver,string content) throws messagingexception
    {
        if (smtphost == null) throw new messagingexception("smtphost not found");
        if (user == null) throw new messagingexception("user not found");
        if (password == null) throw new messagingexception("password not found");

        properties properties = new properties();
        properties.put("mail.smtp.host", smtphost);//设置smtp主机
        properties.put("mail.smtp.auth", "true");//使用smtp身份验证

        session session = session.getdefaultinstance(properties,
             new authenticator(){
               public passwordauthentication getpasswordauthentication(){
                 return new passwordauthentication(user, password);
               }
             });

        //获得邮件会话对象
        mimemessage mimemsg = new mimemessage(session);//创建mime邮件对象
        if (sender != null)//设置发件人地址
            {
                mimemsg.setfrom(new internetaddress(sender));
            }
        if (receiver != null)//设置收件人地址
           {
               mimemsg.setrecipients(message.recipienttype.to, parse(receiver));
           }
        if (subject != null)//设置邮件主题
           {
               mimemsg.setsubject(subject, "gbk");
           }
        mimebodypart part = new mimebodypart();//mail内容部分
        part.settext(content == null ? "" : content, "gbk");

        //设置邮件格式为html cqc
        part.setcontent(content.tostring(),"text/html;charset=gbk");
        multipart multipart = new mimemultipart();
        multipart.addbodypart(part);//在 multipart 中增加mail内容部分
        mimemsg.setcontent(multipart);//增加 multipart 到信息体
        mimemsg.setsentdate(new date());//设置发送日期
        transport.send(mimemsg);//发送邮件
    }

    /** 解析地址集合字符串 */
    private internetaddress[] parse(string addressset) throws addressexception
    {
        arraylist list = new arraylist();
        stringtokenizer tokens = new stringtokenizer(addressset, ";");
        while (tokens.hasmoretokens())
        {
            list.add(new internetaddress(tokens.nexttoken().trim()));
        }
        internetaddress[] addressarray = new internetaddress[list.size()];
        list.toarray(addressarray);
        return addressarray;
    }

    /**
     *  供外部调用的接口
     */
  
    public boolean sendmails(string mail,string content)
    {
        int maillen = 0 ;
        int contentlen= 0;
        if (mail == null||content==null)
        {
            return false;
        }

            try
            {
                this.smtp(mail,content);
            }
            catch(exception ex)
            {
                system.err.println("ex2 in sendmail.java:"+ex.tostring());
            }

        return true;
    }

         public static void main (string[] args)
     {
         sendmail mail = new sendmail();
         string email = "feng_lei@ecfounder.com;ladofwind@163.com";
         string content = "账号:123 密码:123 <br/>感谢您注册!<br/><a href='http://www.xxxx.com.cn' target='_blank'>www.xxxx.com.cn</a><br/>此致<br/>xxxx <br/>即日";
         try
         {
             mail.sendmails(email,content);
         }
         catch (exception ex)
         {
            system.err.println("ex33:"+ex.tostring());
         }
     }

 }

编译通过后,在class文件的目录下建立一个文本文件mailserver.properties,
格式:
smtphost=smtp.163.com
user=user
password=pwd
sender=csdn@csdn.com
subject=hello


运行程序即可实现邮件发送!