引入

  <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-mail</artifactId>
  </dependency>

  mail:
    username: 48303354@qq.com
    password: XXXX
    host: smtp.qq.com
    properties.mail.smtp.ssl.enable: true

@SpringBootTest
public class test {

    @Autowired
    JavaMailSenderImpl mailSender;

    @Test
    void contextloads(){
        SimpleMailMessage message=new SimpleMailMessage();
        message.setSubject("java mail测试");
        message.setText("我的第一封java邮件");
        message.setFrom("48303354@qq.com");
        message.setTo("48303354@qq.com");

        mailSender.send(message);
    }


    @Test
    void contextloads2() throws MessagingException {
        //一个复杂的邮件
        MimeMessage mimeMessage=mailSender.createMimeMessage();
        //组装
        MimeMessageHelper helper=new MimeMessageHelper(mimeMessage,true);
        //正文

        helper.setSubject("java mail测试");
        helper.setText("<p style='color:red;font-size:24;text-align:center'>我的第一封java邮件</p>",true);
        helper.setFrom("48303354@qq.com");
        helper.setTo("48303354@qq.com");

        mailSender.send(mimeMessage);
    }
}