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

@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({ MimeMessage.class, MimeType.class, MailSender.class })
@ConditionalOnMissingBean(MailSender.class)
@Conditional(MailSenderCondition.class)	
@EnableConfigurationProperties(MailProperties.class)			//配置文件綁定
@Import({ MailSenderJndiConfiguration.class, MailSenderPropertiesConfiguration.class })
public class MailSenderAutoConfiguration {

	static class MailSenderCondition extends AnyNestedCondition {

		MailSenderCondition() {
			super(ConfigurationPhase.PARSE_CONFIGURATION);
		}
		// 配置文件前綴名稱(chēng)
		@ConditionalOnProperty(prefix = "spring.mail", name = "host")
		static class HostProperty {

		}

		@ConditionalOnProperty(prefix = "spring.mail", name = "jndi-name")
		static class JndiNameProperty {

		}
	}
}

spring:
  mail:
    username: xxxx@163.com
    password: 授權(quán)碼
    host: smtp.163.com				# 不同郵箱對(duì)應(yīng)的服務(wù)器不一樣
    default-encoding: UTF-8
    
#    username: xxxx@qq.com
#    password: 授權(quán)碼
#    host: smtp.qq.com

@Configuration
@EnableAsync//開(kāi)啟異步
public class ThreadPoolConfig {

    @Bean("threadPool")
    public TaskExecutor taskExecutor() {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        // 設(shè)置核心線(xiàn)程數(shù)
        executor.setCorePoolSize(5);
        // 設(shè)置最大線(xiàn)程數(shù)
        executor.setMaxPoolSize(10);
        // 設(shè)置隊(duì)列容量
        executor.setQueueCapacity(100);
        // 設(shè)置線(xiàn)程活躍時(shí)間（秒）
        executor.setKeepAliveSeconds(60);
        // 設(shè)置默認(rèn)線(xiàn)程名稱(chēng)
        executor.setThreadNamePrefix("Thread-");
        // 設(shè)置拒絕策略
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        // 等待所有任務(wù)結(jié)束后再關(guān)閉線(xiàn)程池
        executor.setWaitForTasksToCompleteOnShutdown(true);
        return executor;
    }
}

public class EmailUtil {

    private static final String content = "這是郵件的主內(nèi)容";
	
	// 純文本郵件
    public static SimpleMailMessage simple(String from, String to){
        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(from);
        message.setTo(to);
        message.setSubject("歡迎xxx");
        message.setText(content);
        return message;
    }

	// 多媒體郵件
    public static MimeMessage mimeMessage(MimeMessage message,String from, String to) throws MessagingException {
        MimeMessageHelper helper = new MimeMessageHelper(message,true);
        helper.setFrom(from);
        helper.setTo(to);
        helper.setSubject("復(fù)雜郵件主題");
        helper.setText("<p style='color: deepskyblue'>這是淺藍(lán)色的文字</p>", true);
        helper.addAttachment("1.docx", new File("C:\\Users\\Splay\\Desktop\\說(shuō)明書(shū).docx"));
        helper.addAttachment("1.pdf", new File("C:\\Users\\Splay\\Desktop\\參考.pdf"));
        return message;
    }
}

@Service
public class SendEmailService {

	// SpringBoot自動(dòng)裝配的郵件發(fā)送實(shí)現(xiàn)類(lèi)
    @Autowired
    JavaMailSenderImpl mailSender;

    @Async("threadPool")
    public void sendSimpleMail(String from, String to) {
        SimpleMailMessage message = EmailUtil.simple(from, to);
        mailSender.send(message);                   //簡(jiǎn)單純文本郵件發(fā)送
    }

    @Async("threadPool")
    public void sendMultiPartMail(String from, String to) throws MessagingException {
        MimeMessage message = mailSender.createMimeMessage();
        MimeMessage mimeMessage = EmailUtil.mimeMessage(message,from, to);
        mailSender.send(mimeMessage);               //復(fù)雜郵件發(fā)送
    }

}

@Controller
public class RouterController {

    @Value("${spring.mail.username}")
    private String from;


    @Autowired
    SendEmailService mail;

    @RequestMapping("/simple")
    @ResponseBody
    public String simpleMail(@RequestParam(required = true,name = "mail",defaultValue = "xxx@qq.com") String to) {
        mail.sendSimpleMail(from, to);
        return "Send SimpleEmail Successful!";
    }

    @RequestMapping("/complex")
    @ResponseBody
    public String complexMail(@RequestParam(required = true,name = "mail",defaultValue = "xxx@qq.com") String to) throws MessagingException {
        mail.sendMultiPartMail(from, to);
        return "Send SimpleEmail Successful!";
    }
}