我的邮件发送为什么老是不对

Properties posts = new Properties();
posts.put("mail.smtp.host","smtp.163.com");
Session mailSession = Session.getInstance(posts);
mailSession.setDebug(true);
MailAuthenticator myAuth = new MailAuthenticator(null, null);
Message mailMessage = new MimeMessage(mailSession);
mailMessage.setFrom(new InternetAddress(request.getParameter("UName")));
mailMessage.addRecipient(Message.RecipientType.TO,new InternetAddress(request.getParameter("[email protected]")));
mailMessage.setSubject(request.getParameter("tmpsubject"));
mailMessage.setText(request.getParameter("tmpcontent"));
mailMessage.saveChanges();
Transport transport=mailSession.getTransport("stmp");
transport.connect();
transport.sendMessage(mailMessage,mailMessage.getAllRecipients());
transport.close();
我想在发送邮件的时候不需要做用户身份的验证，所以我吧用户名和密码都设置成了空，这样有问题吗？