Why i cant't remove the headers mail with this code ?

			

			// Get folder
			

			Folder folder = store.getFolder("INBOX");
			

			folder.open(Folder.READ_WRITE);
			

			BufferedReader reader = new BufferedReader (
			

			new InputStreamReader(System.in));
			

			

			// Get directory
			

			Message message[] = folder.getMessages();
			

			for (int i=0, n=message.length; i
			

			System.out.println("Message "+i+" :");
			

			try{
			

			for (Enumeration e = message[i].getAllHeaders(); e.hasMoreElements();)
			

			{
			

			Header header =(Header)e.nextElement();
			

			message[i].removeHeader(header.getName());
			

			System.out.println("Headers remove!");
			

			}
			

			}
			

			catch (IllegalWriteException ie)
			

			{
			

			System.out.println("POP3 Messages are read-only");
			

			}
			

		

Although i open the folder in read-write, the message is : POP3 Messages are read-only.

Can somebody help me?