懂javaMail的请来指点

 本人写的发邮件程序发给163.com老是不行，还有其他的如雅虎也不行，但是发给自己的邮件服务器可以请指点

package com.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import java.util.Properties;

import javax.mail.Message;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

 

public class SEND1 extends HttpServlet {

 public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {

  response.setContentType("text/html");
  PrintWriter out = response.getWriter();
  request.setCharacterEncoding("gb2312");
  
  String from = request.getParameter("from");
  String to = request.getParameter("to");
  String subject = request.getParameter("subject");
  String context = request.getParameter("context");
  String type=request.getParameter("type");
  // 确定要发送的邮件服务器的地址
  String mailserver = "163.com";
  // 设置邮件的传输协议
  try {
   Properties prop = System.getProperties();
   prop.put("mail.smtp.host", mailserver);
   // 建立邮件发送的连接
   Session session = Session.getDefaultInstance(prop, null);
   // 创建发送的信息的载体
   Message msg = new MimeMessage(session);
   // 设置相关的邮件属性
   msg.setFrom(new InternetAddress(from));
   // 点到点的发送
   msg.setRecipient(Message.RecipientType.TO, new InternetAddress(to));
   /*
    * //群发 msg.setRecipients(Message.RecipientType.TO, new
    * InternetAddress[]{new InternetAddress(to),new
    * InternetAddress(to)}); //借助循环的标准发送
    */
   msg.setSubject(subject);
   msg.setSentDate(new Date());
   //判断发送的Mime类型
   Multipart mp=new MimeMultipart();
   MimeBodyPart mbp=new MimeBodyPart();
   //设置邮件发送数据的类型
   mbp.setContent(context, type+";charset=GB2312");
   //text/plain或text/html;charset=GB2312,将发送的数据进行封装
   mp.addBodyPart(mbp);
   msg.setContent(mp);
   // 发送
   Transport.send(msg);
  } catch (Exception e) {

  }

  out.print("send ok");
  out.flush();
  out.close();
 }

}
下面是jsp页面

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>JavaMail1.html</title>
  </head>
 
  <body>
 
  <form action="SEND" method="post">
  From:<input name="from" ><br>
  TO:<input name="to" ><br>
  Subject:<input name="subject" ><br>
  Context:<textarea rows="40" cols="30" name="context"></textarea><br>
  <input type="submit">
  </form>
   </body>
</html>

 

 

就不行了不知道是163收件箱的地址没写对还是别的试了好多都不行，请指点