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

spring.mail.host=smtp.qq.com 
spring.mail.username=用户名 //发送方的邮箱
spring.mail.password=密码 //对于qq邮箱而言 密码指的就是发送方的授权码
spring.mail.properties.mail.smtp.auth=true 
spring.mail.properties.mail.smtp.starttls.enable=true
spring.mail.properties.mail.smtp.starttls.required=true

@Service 
public class MailService { 
  private final Logger logger = LoggerFactory.getLogger(this.getClass()); 
  @Autowired 
  private JavaMailSender sender; 
  @Value("${spring.mail.username}") 
  private String from; 
  /** 
   * 发送纯文本的简单邮件 
   * @param to 
   * @param subject 
   * @param content 
   */ 
  public void sendSimpleMail(String to, String subject, String content){ 
    SimpleMailMessage message = new SimpleMailMessage(); 
    message.setFrom(from); 
    message.setTo(to); 
    message.setSubject(subject); 
    message.setText(content); 
    try { 
      sender.send(message); 
      logger.info("简单邮件已经发送。"); 
    } catch (Exception e) { 
      logger.error("发送简单邮件时发生异常！", e); 
    } 
  } 
  /** 
   * 发送html格式的邮件 
   * @param to 
   * @param subject 
   * @param content 
   */ 
  public void sendHtmlMail(String to, String subject, String content){ 
    MimeMessage message = sender.createMimeMessage(); 
    try { 
      //true表示需要创建一个multipart message 
      MimeMessageHelper helper = new MimeMessageHelper(message, true); 
      helper.setFrom(from); 
      helper.setTo(to); 
      helper.setSubject(subject); 
      helper.setText(content, true); 
      sender.send(message); 
      logger.info("html邮件已经发送。"); 
    } catch (MessagingException e) { 
      logger.error("发送html邮件时发生异常！", e); 
    } 
  } 
  /** 
   * 发送带附件的邮件 
   * @param to 
   * @param subject 
   * @param content 
   * @param filePath 
   */ 
  public void sendAttachmentsMail(String to, String subject, String content, String filePath){ 
    MimeMessage message = sender.createMimeMessage(); 
    try { 
      //true表示需要创建一个multipart message 
      MimeMessageHelper helper = new MimeMessageHelper(message, true); 
      helper.setFrom(from); 
      helper.setTo(to); 
      helper.setSubject(subject); 
      helper.setText(content, true); 
      FileSystemResource file = new FileSystemResource(new File(filePath)); 
      String fileName = filePath.substring(filePath.lastIndexOf(File.separator)); 
      helper.addAttachment(fileName, file); 
      sender.send(message); 
      logger.info("带附件的邮件已经发送。"); 
    } catch (MessagingException e) { 
      logger.error("发送带附件的邮件时发生异常！", e); 
    } 
  } 
  /** 
   * 发送嵌入静态资源（一般是图片）的邮件 
   * @param to 
   * @param subject 
   * @param content 邮件内容，需要包括一个静态资源的id，比如：<img src=\"cid:rscId01\" > 
   * @param rscPath 静态资源路径和文件名 
   * @param rscId 静态资源id 
   */ 
  public void sendInlineResourceMail(String to, String subject, String content, String rscPath, String rscId){ 
    MimeMessage message = sender.createMimeMessage(); 
    try { 
      //true表示需要创建一个multipart message 
      MimeMessageHelper helper = new MimeMessageHelper(message, true); 
      helper.setFrom(from); 
      helper.setTo(to); 
      helper.setSubject(subject); 
      helper.setText(content, true); 
      FileSystemResource res = new FileSystemResource(new File(rscPath)); 
      helper.addInline(rscId, res); 
      sender.send(message); 
      logger.info("嵌入静态资源的邮件已经发送。"); 
    } catch (MessagingException e) { 
      logger.error("发送嵌入静态资源的邮件时发生异常！", e); 
    } 
  } 
}

public class MailTests extends BasicUtClass{ 
  @Autowired 
  private MailService mailService; 
  private String to = "xujijun@mail.cn"; 
  @Test 
  public void sendSimpleMail() { 
    mailService.sendSimpleMail(to, "主题：简单邮件", "测试邮件内容"); 
  } 
}