http://www.cnblogs.com/wxc-xiaohuang/p/9532631.html
https://blog.csdn.net/icannotdebug/article/details/79725297
https://docs.spring.io/spring/docs/4.3.21.RELEASE/spring-framework-reference/htmlsingle/#mail
Spring Boot使用JavaMailSender发送邮件
原文：https://www.cnblogs.com/diyunpeng/p/10056417.html