Links to review:

https://wordpress.org/plugins/subscribe-to-category/

http://www.wpbeginner.com/wp-tutorials/how-to-allow-users-to-subscribe-to-categories-in-wordpress/

https://moz.com/community/q/wordpress-plugin-for-email-subscription-to-different-categories

Home

9 WordPress Category Plugins to Get The Most Out of Your Blog

https://wordpress.org/support/plugin/wysija-newsletters/

https://wordpress.org/plugins/category-posts/

http://www.wpbeginner.com/wp-tutorials/10-most-wanted-category-hacks-and-plugins-for-wordpress/

http://www.wpbeginner.com/wp-tutorials/how-to-display-category-descriptions-in-wordpress/