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

public class ReplyExample {
  public static void main (String args[]) throws Exception {
    String host = args[0];
    String sendHost = args[1];
    String username = args[2];
    String password = args[3];
    String from = args[4];

    // Create empty properties
    Properties props = System.getProperties();
    props.put("mail.smtp.host", sendHost);

    // Get session
    Session session = Session.getDefaultInstance(props, null);

    // Get the store
    Store store = session.getStore("pop3");
    store.connect(host, username, password);

    // Get folder
    Folder folder = store.getFolder("INBOX");
    folder.open(Folder.READ_ONLY);

    BufferedReader reader = new BufferedReader (
      new InputStreamReader(System.in));

    // Get directory
    Message message[] = folder.getMessages();
    for (int i=0, n=message.length; i<n; i++) {
       System.out.println(i + ": " + message[i].getFrom()[0] 
         + "\t" + message[i].getSubject());

      System.out.println("Do you want to reply to the message? [YES to reply/QUIT to end]");
      String line = reader.readLine();
      if ("YES".equals(line)) {

        // Create a reply message
        MimeMessage reply = (MimeMessage)message[i].reply(false);

        // Set the from field
        reply.setFrom(new InternetAddress(from));

        // Create the reply content, copying over the original if text
        MimeMessage orig = (MimeMessage)message[i];
        StringBuffer buffer = new StringBuffer("Thanks\n\n");
        if (orig.isMimeType("text/plain")) {
          String content = (String)orig.getContent();
          StringReader contentReader = new StringReader(content);
          BufferedReader br = new BufferedReader(contentReader);
          String contentLine;
          while ((contentLine = br.readLine()) != null) {
            buffer.append("> ");
            buffer.append(contentLine);
            buffer.append("\r\n");
          }
        }

        // Set the content
        reply.setText(buffer.toString());

        // Send the message
        Transport.send(reply);

      } else if ("QUIT".equals(line)) {
        break;
      }
    }

    // Close connection 
    folder.close(false);
    store.close();
  }
}