Problem downloading attachments in Gmail

Question

Hello,
I'm developing an application that sends mails with attachments from one gmail account to another gmail account and then I download those mails. The problem is that I can check the mails via pop3 and print their envelopes and that stuff but when I get the attachment via the dataHandler and getInputStream the message disappears from the message count and it's not possible to download it again, although if I enter to the gmail account the message is not even checked as read.
Can you help me? Thanks.

Answer 1

Ok so here it is the code for fetching mails with pop3. If I comment the "element.getDataHandler().getInputStream()" the mail doesn't disappear but then I can't get the attachment.
public void connect() throws Exception {
          String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
          Properties pop3Props = new Properties();
          pop3Props.setProperty("mail.pop3.socketFactory.class", SSL_FACTORY);
          pop3Props.setProperty("mail.pop3.socketFactory.fallback", "false");
          pop3Props.setProperty("mail.pop3.port", "995");
          pop3Props.setProperty("mail.pop3.socketFactory.port", "995");
          pop3Props.setProperty("mail.pop3.rsetbeforequit", "true");
          URLName url = new URLName("pop3", "pop.gmail.com", 995, "", this.username, this.password);
          this.session = Session.getInstance(pop3Props, null);
          this.store = new POP3SSLStore(this.session, url);
          this.store.connect();
public void openFolder(String folderName) throws Exception {
          // Open the Folder
          this.folder = this.store.getDefaultFolder();
          this.folder = this.folder.getFolder(folderName);
          if (this.folder == null) {
               throw new Exception("Invalid folder");
          // try to open read/write and if that fails try read-only
          try {
               this.folder.open(Folder.READ_WRITE);
          } catch (MessagingException ex) {
               this.folder.open(Folder.READ_ONLY);
public void saveAttachment(String messageSubject, String path, String fileName) throws Exception {
Message[] msgs = this.folder.getMessages();
          // Use a suitable FetchProfile
          FetchProfile fp = new FetchProfile();
          fp.add(FetchProfile.Item.ENVELOPE);
          this.folder.fetch(msgs, fp);
          for (Message element : msgs) {
               if (element.getSubject().equals(messageSubject)){
                    System.out.println("MESSAGE " + element.getSubject() + ": Found! :)");
                    saveFile(path + fileName, element.getDataHandler().getInputStream());
                    break;
  public static void saveFile(String filename,
           InputStream input) throws IOException {
         if (filename == null) {
           filename = File.createTempFile("xx", ".out").getName();
         // Do no overwrite existing file
         File file = new File(filename);
         for (int i=0; file.exists(); i++) {
           file = new File(filename+i);
         FileOutputStream fos = new FileOutputStream(file);
         BufferedOutputStream bos = new BufferedOutputStream(fos);
         BufferedInputStream bis = new BufferedInputStream(input);
         int aByte;
         while ((aByte = bis.read()) != -1) {
           bos.write(aByte);
         bos.flush();
         bos.close();
         bis.close();
       }