一个发邮件的例子

import javax.mail.*;
import javax.mail.internet.*;
import java.util.Properties;
import java.util.Date;

public class sendMail
{
    public static void main(String args[]) throws Exception
    {

//        String host = "smtp.sina.com.cn";
        String host = "smtp.163.com";
        String from =  "[e-mail]";
//发送的邮件
        String to = "[e-mail]";
        String to2 = [e-mail];
        String username = "test";
        String password = "passwd";
        String fileAttachment = "G:\\Documents and Settings\\aaa\\My Documents\\My eBooks\\附件.txt";

        // Get system properties
        Properties props = new Properties();

        // Setup mail server
        props.put("mail.smtp.host", host);
        props.put("mail.smtp.auth", "true"); 
        // Get session
        Session session = Session.getDefaultInstance(props);

        // watch the mail commands go by to the mail server
        session.setDebug(true);

        // Define message
        MimeMessage message = new MimeMessage(session);
        message.setFrom(new InternetAddress(from));
        message.addRecipient(Message.RecipientType.TO,
          new InternetAddress(to));
        message.addRecipient(Message.RecipientType.TO,
          new InternetAddress(to2));

        message.setSubject("标题");
        message.setText("正文");
//        message.setContentLanguage();
//        FileTypeMap
        FileDataSource fds=new FileDataSource(fileAttachment);
//
//
        message.setDataHandler(new DataHandler(fds));

//        message.setDataHandler(
//         new DataHandler(source));
        // Send message
        message.setSentDate(new Date());
        message.saveChanges();
        Transport transport = session.getTransport("smtp");
        transport.connect(host, username, password);
        transport.sendMessage(message, message.getAllRecipients());
        System.out.println("over");
        transport.close();
    }
}