1. 首先加入pom依赖

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

2.编写配置文件

spring:
  mail:
    host: smtp.qq.com
    username: xxx@qq.com
    password: 自己的授权码
    properties.mail.smtp.ssl.enable: true(QQ邮箱特有的,开启加密验证)

点击开启发送短信会得到授权码，QQ邮箱->设置->账户->往下滑

3.进行发送邮件即可

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

@SpringBootTest
class SpringbootTaskApplicationTests {

    @Autowired
    JavaMailSender javaMailSender; //邮件发送

    /**
     *  简单邮件 发送
     */
    @Test
    void contextLoads() {

        SimpleMailMessage simpleMailMessage = new SimpleMailMessage();
    //邮件设置值
        simpleMailMessage.setSubject("测试邮件-java邮件任务");//邮件主题
        simpleMailMessage.setText("测试邮件,测试java发送邮件任务......");//邮件内容
        simpleMailMessage.setTo("xxxxxxxx@qq.com");//邮件发给谁
        simpleMailMessage.setFrom("xxxxxxxxx@qq.com"); //邮件来自于谁
        javaMailSender.send(simpleMailMessage);
}

    /**
     * 复杂邮件
     */
    @Test
    void contextLoads2() throws Exception {

        MimeMessage mimeMessage = javaMailSender.createMimeMessage();
        MimeMessageHelper mimeMessageHelper=new MimeMessageHelper(mimeMessage,true);
        //邮件设置值
        mimeMessageHelper.setSubject("测试邮件-java邮件任务(复杂邮件)");//邮件主题
        mimeMessageHelper.setText("<b style='color:red'>测试邮件,测试java发送邮件任务......</b>",true);//邮件内容
        //邮件 附件
        mimeMessageHelper.addAttachment("ceshi1.jpg",new File("C:\\Users\\57132\\Desktop\\ceshi1.png"));
        mimeMessageHelper.addAttachment("ceshi2.jpg",new File("C:\\Users\\57132\\Desktop\\ceshi2.png"));
        mimeMessageHelper.setTo("xxxxxx@qq.com");//邮件发给谁
        mimeMessageHelper.setFrom("xxxxxx@qq.com"); //邮件来自于谁
        javaMailSender.send(mimeMessage);
    }
}

请注意！发送邮箱时邮箱的内容不能为空！

即！

mimeMessageHelper.setText("不能为空",true);//邮件内容