SpringBoot 2.1.1.RELEASE 集成Email
依赖配置：
<!-- mail start -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-mail</artifactId>
</dependency>配置文件：
### mail邮件配置
spring.mail.host=smtp.xxx.com.cn
[email protected]
spring.mail.password=xxxx
spring.mail.default-encoding=UTF-8
spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.starttls.enable=true
spring.mail.properties.mail.smtp.starttls.required=true