import java.util.Properties;

import javax.mail.Authenticator;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Store;

public class MainClass {

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

Properties props = new Properties();

String host = "yourserver.edu";
String provider = "pop3";

Session session = Session.getDefaultInstance(props, new MailAuthenticator());
Store store = session.getStore(provider);
store.connect(host, null, null);

Folder inbox = store.getFolder("INBOX");
if (inbox == null) {
System.out.println("No INBOX");
System.exit(1);
}
inbox.open(Folder.READ_ONLY);

Message[] messages = inbox.getMessages();
for (int i = 0; i < messages.length; i++) {
System.out.println("Message " + (i + 1));
messages[i].writeTo(System.out);
}
inbox.close(false);
store.close();
}
}

class MailAuthenticator extends Authenticator {

public MailAuthenticator() {
}

public PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication("username", "password");
}
}