一段群发邮件的代码

import javax.mail.*;
import javax.mail.internet.*;
import java.sql.*;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import javax.activation.*;

public class MailAccess {

	public static void main(String[] args) {

		ResultSet rs = null;
		int sendCount = 1;
		String from = "brue";
		String to = null;
		String fromname = "发件人名称";
		String subject = "关于XXX的通知";
		String type = "text/html";
                      //附件的本地地址
		String[] fileAttachment = { "d:\\通知1.gif", "d:\\通知2.gif","d:\\报送表.doc" };
                     //群发邮件的地址在access数据库中，读取并循环发送！
		try {
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
			String url = "jdbc:odbc:Driver={MicroSoft Access Driver (*.mdb)};DBQ=d:\\email.mdb";
			Connection con = DriverManager.getConnection(url);
			Statement stmt = con.createStatement();
			String strSQL = "select email from email";
			rs = stmt.executeQuery(strSQL);
			while (rs.next()) {
				to = rs.getString("email");
				StringBuffer str = new StringBuffer();
				str.append("<P>有关成员单位：<BR>全国高校毕业生就业网络联盟成立以来，…………");
 				str.append("招聘信息可免费在www.myjob.edu.cn和www.ncss.org.cn发布。</P>");
				String message = str.toString();
				System.out.println(to);
				sendMail(from, fromname, to, subject, message, fileAttachment,type, sendCount++);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

 

	public static void sendMail(String from, String fromname, String to,
			String subject, String message, String[] fileAttachment,
			String type, int sendCount) throws Exception {
		// 以下是发送邮件的代码
		InternetAddress[] address = null;
		String mailserver = "mail.myjob.edu.cn";
		boolean sessionDebug = false;
		try {

			// 设定所要用的Mail 服务器和所使用的传输协议
			java.util.Properties props = System.getProperties();
			props.put("mail.host", mailserver);
			props.put("mail.transport.protocol", "smtp");
			props.put("mail.smtp.auth", "true");// 指定是否需要SMTP验证

			// 产生新的Session 服务
			javax.mail.Session mailSession = javax.mail.Session
					.getDefaultInstance(props, null);
			mailSession.setDebug(sessionDebug);
			Message msg = new MimeMessage(mailSession);

			// 设定发邮件的人
			msg.setFrom(new InternetAddress(from, MimeUtility.encodeText(
					fromname, "gb2312", "b")));

			// 设定收信人的信箱
			address = InternetAddress.parse(to, false);
			msg.setRecipients(Message.RecipientType.TO, address);

			// 设定信中的主题
			msg.setSubject(subject);

			// 设定送信的时间
			msg.setSentDate(new java.util.Date());

			Multipart mp = new MimeMultipart();
			MimeBodyPart mbp = new MimeBodyPart();

			// 设定邮件内容的类型为 text/plain 或 text/html
			mbp.setContent(message, type + ";charset=GB2312");
			mp.addBodyPart(mbp);

			// 附件部分
			for (int i = 0; i < fileAttachment.length; i++) {
				MimeBodyPart messageBodyPart = new MimeBodyPart();
				FileDataSource fds = new FileDataSource(fileAttachment[i]);
				messageBodyPart.setDataHandler(new DataHandler(fds));
				//支持中文文件名
				messageBodyPart.setFileName(MimeUtility.encodeWord(fds
						.getName(), "GB2312", null));
				mp.addBodyPart(messageBodyPart);
			}
			msg.setContent(mp);

			Transport transport = mailSession.getTransport("smtp");
		               //邮箱用户名和密码
			transport.connect(mailserver, "username", "password");
			transport.sendMessage(msg, msg.getAllRecipients());
			transport.close();
			System.out.println("成功发送 " + sendCount + " 封");

		} catch (MessagingException mex) {
			mex.printStackTrace();
			System.out.println(mex);
		}
	}

  

   上边群发的原理是使用了while循环调用sendMail方法，虽然能实现，但是更简单、更实用的方法如下所示：
    取得必要的Transport对象并调用SendMessage（）发送每一个邮件。注意在调用之间设置或改变接收者。

  

		Message message = …;
			Transport t = session.getTransport("smtp");
			t.connect();
			message.setRecipient(Message.RecipientType.TO,recipient1);
			t.sendMessage(message,recipient);
			message.setRecipient(Message.RecipientType.TO,recipient2);
			t.sendMessage(message,recipient);
			message.setRecipient(Message.RecipientType.TO,recipient3);
			t.sendMessage(message,recipient);
			t.close();  

 

   程序也是从网上参考着凑出来的， 有什么不足之处，还望大家不吝赐教！