[add]:

1. (common) pom.xml - 增加邮件依赖 ;
2. (admin) application-dev.yml - 增加邮件配置 ;
3. (framework) MailProperties, MailConfig - 增加邮件属性配置 ;
4. (common) MailUtils - 重写 Hutool MailUtil方法 ;
5. (demo) MailController - 邮件发送测试方法 ;

ruoyi-common/pom.xml

@@ -159,6 +159,12 @@
             <artifactId>lock4j-redisson-spring-boot-starter</artifactId>
         </dependency>
 
+        <dependency>
+            <groupId>com.sun.mail</groupId>
+            <artifactId>javax.mail</artifactId>
+            <version>${mail.version}</version>
+        </dependency>
+
     </dependencies>
 
 </project>