[Error] Java Mail Sender @Autowired 오류

• JavaMailSender가 Autowired로 주입되지 않을 때

	@Autowired
	private JavaMailSender mailSender;

	@Bean
	public JavaMailSenderImpl mailSender() {
		JavaMailSenderImpl javaMailSender = new JavaMailSenderImpl();
		javaMailSender.setProtocol("smtp");
		javaMailSender.setHost("127.0.0.1");
		javaMailSender.setPort(25);
		return javaMailSender;
	}