Java郵件Api不返回所有郵件

嗨我想獲取Gmail收件箱的所有郵件，但它沒有返回所有郵件。它返回的郵件太舊了。不是最新的。我用下面的代碼測試：Java郵件Api不返回所有郵件

public class ReadEmail { 

    public static void check(String host, String storeType, final String user, final String password) { 
     try { 

      // create properties field 
      Properties properties = new Properties(); 

      properties.put("mail.pop3.host", host); 
      properties.put("mail.pop3.port", "995"); 
      properties.put("mail.pop3.starttls.enable", "true"); 
      Session emailSession = Session.getDefaultInstance(properties); 
      emailSession.setDebug(true); 

      // create the POP3 store object and connect with the pop server 
      Store store = emailSession.getStore("pop3s"); 

      store.connect(host, user, password); 

      // create the folder object and open it 
      Folder emailFolder = store.getFolder("Inbox"); 
      emailFolder.open(Folder.READ_ONLY); 

      // retrieve the messages from the folder in an array and print it 
      Message[] messages = emailFolder.getMessages(); 
      System.out.println("messages.length---" + messages.length); 

      // close the store and folder objects 
      emailFolder.close(false); 
      store.close(); 

     } catch (NoSuchProviderException e) { 
      e.printStackTrace(); 
     } catch (MessagingException e) { 
      e.printStackTrace(); 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
    } 

    public static void main(String[] args) { 

     String host = "pop.gmail.com"; 
     String mailStoreType = "pop3"; 
     String username = "****@gmail.com";// change accordingly 
     String password = "****";// change accordingly 

     check(host, mailStoreType, username, password); 

    } 
}