J2ME SMTP / POP3 Connection

Hi all,

I've created a midlet which also should send and receive Emails via SocketConnections (I'm using a Sony Ericsson P900 with MIDP 2.0 and GPRS-Connection).
While sending and receiving emails works in the emulator, it doesn't on the mobile. It seems he doesn't leave the while-loop (Reading InputStream).
I send a quit command in both cases, but somehow the InputStream doesn't seem to end...i have no more ideas. Would be great if anyone could help me - would be urgent!
The code for sending and receiving emails is the following:

  public void sendEmail() {

     try {
       sc = (SocketConnection) Connector.open("socket://" + smtpServerAdress + ":25");
       is = sc.openInputStream();
       os = sc.openOutputStream();
       sb = new StringBuffer();
     
       // Send SMTP-Commands
       os.write(("HELO" + domain + "\r\n").getBytes());
       os.write(("MAIL FROM: "+ from_emailAdress +"\r\n").getBytes());
       os.write(("RCPT TO: "+ to_emailAdress + "\r\n").getBytes());
       os.write("DATA\r\n".getBytes());
       os.write(("Date: " + new Date() + "\r\n").getBytes());
       os.write(("From: "+ from_emailAdress +"\r\n").getBytes());
       os.write(("To: "+ to_emailAdress +"\r\n").getBytes());
       os.write(("Subject: MIAM TEST\r\n").getBytes());
       os.write(("TESTMESSAGE FROM MIAM \r\n").getBytes());
       os.write(".\r\n".getBytes());
       os.write("QUIT\r\n".getBytes());

       int c = 0;
     
       // DOESN'T LEAVE LOOP
       while (  (c = is.read() ) != -1)  {
          sb.append( (char)c);

     }

     System.out.println(sb.toString());
   }
   catch (Exception e) {
     e.printStackTrace();
   }

   finally {
        try {
           if(is != null) {
              is.close();
           }
           if(os != null) {
              os.close();
           }
           if(sc != null) {
              sc.close();
           }
        } catch(IOException e) {
           e.printStackTrace();
        }
     }

 }

  public void getEmail() {

    try {
      sc = (SocketConnection) Connector.open("socket://" + popServerAdress + ":110");
      is = sc.openInputStream();
      os = sc.openOutputStream();
      sb = new StringBuffer();

      int ch = 0;
      os.write( ("USER " + userName + "\r\n").getBytes());
      os.write( ("PASS " + userPass + "\r\n").getBytes());
      os.write( ("LIST" + "\r\n").getBytes());
      os.write( ("RETR 1" + "\r\n").getBytes());
      os.write("QUIT\r\n".getBytes());

      while ( (ch = is.read() ) != -1) {
           sb.append( (char) ch);
      }
        System.out.println(sb.toString());
    }

    catch (Exception e) {
      e.printStackTrace();

    }
    finally {
         try {
            if(is != null) {
               is.close();
            }
            if(os != null) {
               os.close();
            }
            if(sc != null) {
               sc.close();
            }
         } catch(IOException e) {
           e.printStackTrace();
         }
      }
  }

Regards,