无法使用JavaMailSender和Spring Boot发送带有附件的邮件

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.mail.MailProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.boot.mail.javamail.JavaMailSender;
import org.springframework.boot.mail.javamail.JavaMailSenderImpl;
import org.springframework.context.annotation.Bean;
import org.springframework.mail.javamail.MimeMessageHelper;

import javax.mail.MessagingException;
import javax.mail.internet.MimeMessage;
import java.io.File;

@SpringBootApplication
@EnableConfigurationProperties(MailProperties.class)
public class Application {

    @Autowired
    private JavaMailSender javaMailSender;

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @Bean
    public JavaMailSender javaMailSender(MailProperties mailProperties) {
        JavaMailSenderImpl mailSender = new JavaMailSenderImpl();
        mailSender.setHost(mailProperties.getHost());
        mailSender.setPort(mailProperties.getPort());
        mailSender.setUsername(mailProperties.getUsername());
        mailSender.setPassword(mailProperties.getPassword());
        return mailSender;
    }

    public void sendEmailWithAttachment() throws MessagingException {
        MimeMessage message = javaMailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message, true);

        helper.setFrom("sender@example.com");
        helper.setTo("recipient@example.com");
        helper.setSubject("Email with Attachment");
        helper.setText("Please find the attached file.");

        File attachment = new File("path/to/attachment.txt");
        helper.addAttachment("Attachment.txt", attachment);

        javaMailSender.send(message);
    }
}