Error with either GMail or getMessages()

Question

Hi everybody,
I've written a program to backup files to my gmail account. Each of the individual pieces seems to be working, but for some reason, the getMessages() function doesn't get the messages that the program itself has sent. It recognizes email from other clients, but if my program sends it, getMessages() will ignore it. It's there, 'cause I can log in to gmail and view it. Is this a problem with gmail, with getMessages(), or with me?
Below is a simple program to demonstrate the problem. You'll need mail.jar, activation.jar, and pop3.jar in your classpath. It's usage is:
java gmailTest userName password subjectLine
It reads your gmail acct., lists the message subjects, looks for a message with the subject you entered on the command line, then sends a new message with that subject, then checks again for a message with that subject. It should always get a match on the second run, but it doesn't.
I've got gmail invites for anybody who thinks he or she can help.
import java.util.Properties;
import java.util.StringTokenizer;
import java.io.File;
import com.sun.mail.pop3.POP3SSLStore;
import java.security.Security;
import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;
public class gmailTest
public static String usage = "Usage: java gmailTest user password subject";
public static void main(String[] args)
  if(args.length != 3)
   System.out.println(usage);
   System.exit(0);
  Properties pop3Props = new Properties();
  pop3Props.setProperty("mail.pop3.user", args[0]);
  pop3Props.setProperty("mail.pop3.passwd", args[1]);
  pop3Props.setProperty("mail.pop3.ssl", "true");
  pop3Props.setProperty("mail.pop3.host", "pop.gmail.com");
  Properties smtpProps = new Properties();
  smtpProps.setProperty("mail.smtp.user", args[0]);
  smtpProps.setProperty("mail.smtp.passwd", args[1]);
  smtpProps.setProperty("mail.smtp.ssl", "true");
  smtpProps.setProperty("mail.smtp.host", "smtp.gmail.com");
  String toAndFromAddress = pop3Props.getProperty("mail.pop3.user") + "@gmail.com";
  try
   checkForMessage(pop3Props, args[2]);
   sendMail(smtpProps, args[2], null, toAndFromAddress, null, null, toAndFromAddress, null, true);
   checkForMessage(pop3Props, args[2]);
  catch(Exception e)
   e.printStackTrace();
public static  boolean checkForMessage(Properties props, String msgSubject)
        throws NoSuchProviderException, MessagingException
  Session session = null;
  Store store = null;
  String user = ((props.getProperty("mail.pop3.user") != null) ? props.getProperty("mail.pop3.user") : props.getProperty("mail.user"));
  String passwd = ((props.getProperty("mail.pop3.passwd") != null) ? props.getProperty("mail.pop3.passwd") : props.getProperty("mail.passwd"));
  String host = ((props.getProperty("mail.pop3.host") != null) ? props.getProperty("mail.pop3.host") : props.getProperty("mail.host"));
  if((props.getProperty("mail.pop3.ssl") != null) && (props.getProperty("mail.pop3.ssl").equalsIgnoreCase("true")))
   String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
   props.setProperty("mail.pop3.socketFactory.class", SSL_FACTORY);
   props.setProperty("mail.pop3.socketFactory.fallback", "false");
   String portStr = ((props.getProperty("mail.pop3.port") != null) ? props.getProperty("mail.pop3.port") : "995");
   props.setProperty("mail.pop3.port",  portStr);
   props.setProperty("mail.pop3.socketFactory.port", portStr);
   URLName url = new URLName("pop3://"+user+":"+passwd+"@"+host+":"+portStr);
   session = Session.getInstance(props, null);
   store = new POP3SSLStore(session, url);
  else
   session = Session.getInstance(props, null);
   store = session.getStore("pop3");
//session.setDebug(true);
  store.connect(host, user, passwd);
  Folder folder = store.getFolder("INBOX");
  folder.open(Folder.READ_WRITE);
  Message[] allMsgs = folder.getMessages();
  boolean msgFound = false;
  for(int i = 0; i < allMsgs.length; i++)
   System.out.println(allMsgs.getSubject());
if(allMsgs[i].getSubject().equals(msgSubject))
msgFound = true;
if(msgFound)
System.out.println("-----------!!!A Matching Message was found!!!------------");
else
System.out.println("------------------No Matching Messages were found :{--------------------");
folder.close(true);
store.close();
return msgFound;
public static int sendMail(final Properties props, String subject, String body, String to, String cc, String bcc, String from, File[] attachments, boolean toStdOut)
     throws javax.mail.internet.AddressException, javax.mail.MessagingException, javax.mail.NoSuchProviderException
Session sess;
//props.setProperty("mail.debug", "true");
if(props.getProperty("mail.smtp.ssl") != null && props.getProperty("mail.smtp.ssl").equalsIgnoreCase("true"))
Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
String portStr = ((props.getProperty("mail.smtp.port") != null) ? (props.getProperty("mail.smtp.port")) : "465");
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.socketFactory.port", portStr);
props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
props.put("mail.smtp.socketFactory.fallback", "false");
sess = Session.getDefaultInstance(props,
new javax.mail.Authenticator()
protected PasswordAuthentication getPasswordAuthentication()
     String userName = ((props.getProperty("mail.smtp.user") != null) ? props.getProperty("mail.smtp.user") : props.getProperty("mail.user"));
     String passwd = ((props.getProperty("mail.smtp.passwd") != null) ? props.getProperty("mail.smtp.passwd") : props.getProperty("mail.passwd"));
if(userName == null || passwd == null)
return null;
return new PasswordAuthentication(userName , passwd);
else
String portStr = ((props.getProperty("mail.smtp.port") != null) ? (props.getProperty("mail.smtp.port")) : "25");
sess = Session.getInstance(props, null);
//sess.setDebug(true);
MimeMessage mess = new MimeMessage(sess);
mess.setSubject(subject);
StringTokenizer toST = new StringTokenizer(to, ",;");
while(toST.hasMoreTokens())
Address addr = new InternetAddress(toST.nextToken());
mess.addRecipient(Message.RecipientType.TO, addr);
if(from != null)
StringTokenizer fromST = new StringTokenizer(from, ",;");
InternetAddress[] fromAddrs = new InternetAddress[fromST.countTokens()];
for(int i = 0; fromST.hasMoreTokens(); i++)
fromAddrs[i] = new InternetAddress(fromST.nextToken());
mess.addFrom(fromAddrs);
if(cc != null)
StringTokenizer ccST = new StringTokenizer(cc, ",;");
while(ccST.hasMoreTokens())
Address addr = new InternetAddress(ccST.nextToken());
mess.addRecipient(Message.RecipientType.CC, addr);
if(bcc != null)
StringTokenizer bccST = new StringTokenizer(bcc, ",;");
while(bccST.hasMoreTokens())
Address addr = new InternetAddress(bccST.nextToken());
mess.addRecipient(Message.RecipientType.BCC, addr);
BodyPart messageBodyPart = new MimeBodyPart();
Multipart multipart = new MimeMultipart();
if(body != null)
messageBodyPart.setText(body);
multipart.addBodyPart(messageBodyPart);
if(attachments != null)
for(int i = 0; i < attachments.length; i++)
messageBodyPart = new MimeBodyPart();
DataSource source = new FileDataSource(attachments[i]);
messageBodyPart.setDataHandler(new DataHandler(source));
messageBodyPart.setFileName(attachments[i].getName());
multipart.addBodyPart(messageBodyPart);
mess.setContent(multipart);
Address[] allRecips = mess.getAllRecipients();
if(toStdOut)
System.out.println("done.");
//System.out.println("Sending message (\"" + mess.getSubject().substring(0,10) + "...\") to :");
System.out.println("Sending message (\"" + mess.getSubject() + "...\") to :");
for(int i = 0; i < allRecips.length; i++)
System.out.print(allRecips[i] + ";");
System.out.println("...");
Transport.send(mess);
if(toStdOut)
System.out.println("done.");
return 0;

Answer 1

In first place, sorry about my English (I'm spanish).
I think the code is good. I have got a similar problem and I think the problem is from GMAIL.
When I log in in one of my GMAIL accounts and put POP3 enabled (in Settings / Forwarding and Pop ) and don�t logout of the account , I can getmessages without problems, but if I try get the messages when I've logout , getmessages() don�t return messages.
I think the problem is: when you put pop3 enabled in the account say "POP is enabled for all mail that has arrived since", and say the time when you log in and enabled it. When you do a new log in say the new time, it mean, the account don�t remenber that you have set pop enabled and then, when you logout and try getMessages POP is not enabled.
In another account (I have one more old GMAIL account), when I enabled POP3, it remain enabled and i can getMessages from this account without problems.
In resume, log in in your account, PUT enable POP in "Settings / Forwarding and Pop" in the GMAIL account, and without logout try you code.
If you can get the messages, the problems is the same that I had, and it�s caused by that account. Try to get another GMAIL account that remenber the POP enabled selection when you logout.