邮件的回复的代码很简单，在迭代邮件的信息的时候调用MimeMessage reply = (MimeMessage) messages[i].reply(Boolean ) TRUE 是邮件回复给发送者，FALSE恢复给所有人。如果要回复到新的收件人请使用SetReply-to。
同时可以使用 reply.setSubject(“***”)设置回复的标题，不设置的话默认是Re: 加上接收到邮件的标题。同理，也可以自己设置正文内容。
这里一定要设置发送邮件的地址，而且必须要和邮件认证的用户名一致，不然会报错。
最后调用Transport.send(reply)将邮件发出去
注意：1、reply.setFrom() 必须要设置而且要和邮件认证的用户名一致，不然会报以下错误：
com.sun.mail.smtp.SMTPSendFailedException: 501 mail from address must be same as authorization user
2、建议使用邮件认证登陆邮件服务器，不然会出现以下错误：
javax.mail.AuthenticationFailedException: failed to connect, no password specified?
3、代码虽然很简单，但是程序难免会出现各种异常。如果大家在调试程序的时候出现错误，请给我留言。
给一个成功例子大家参考：.
import java.io.*;
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
public class ReplyMail {
private static final String HOST_NAME = "pop.qq.com";
private static final String SEND_HOST_NAME = "smtp.qq.com";
private static final String PASSWORD = "*******";
private static final String EMAIL_FROM = "
flyingsam@qq.com";
private static final String USER_NAME = "
flyingsam@qq.com";
private static final String PROTOCOL = "pop3";
private static final String SEND_PROTOCOL = "smtp";
public static void listMail() throws Exception {
Properties props = new Properties();
props.put("mail.smtp.host", SEND_HOST_NAME);
props.put("mail.pop.host", HOST_NAME);
props.put("mail.transport.protocol","smtp");
props.put("mail.smtp.auth", "true");
Session session = Session.getDefaultInstance(props, new SimpleAuthenticator(USER_NAME, PASSWORD));
Store store = session.getStore(ReplyMail.PROTOCOL);
store.connect(HOST_NAME, USER_NAME, PASSWORD);
Folder folder = store.getFolder("INBOX");
folder.open(Folder.READ_ONLY);
Message[] messages = folder.getMessages();
InternetAddress address;
for (int i = messages.length-1; i >= 0; i--) {
address = (InternetAddress)messages[i].getFrom()[0];
if(address != null) {
System.out.println(address.getPersonal());
}
if (null != address && "秋天的童话".equals(address.getPersonal())) {
System.out.println("第" + i + "个：" + messages[i].getSubject());
MimeMessage replyMessage = (MimeMessage) messages[i].reply(false);
// replyMessage.setFrom(new InternetAddress(EMAIL_FROM));
replyMessage.setRecipients(MimeMessage.RecipientType.TO, address.getAddress());
replyMessage.setText("这是回复邮件，不知道能否成功！");
replyMessage.saveChanges();
Transport transport = session.getTransport("smtp");
transport.connect(SEND_HOST_NAME, USER_NAME, PASSWORD);
transport.send(replyMessage);
System.out.println("回复成功");
}
}
folder.close(true);
store.close();
}
public static void main(String[] args) {
try {
ReplyMail.listMail();
} catch (Exception e) {
e.printStackTrace();
}
}
}
类SimpleAuthenticator的代码：
public class SimpleAuthenticator extends Authenticator {
private String username;
private String password;
public SimpleAuthenticator(String username, String password) {
this.username = username;
this.password = password;
}
public PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(this.username, this.password);
}
}