Preload has been restarted.

I receive an email daily stating “Preload has been restarted” followed by a link https://mydomain.com/wp-admin/options-general.php?page=wpsupercache

I have searched this forum and the Internet to no avail. Does anyone know what this means or what I need to do? It’s unclear if the message began with the upgrade to WP 4.1 or not. Please advise.

https://ww.wp.xz.cn/plugins/wp-super-cache/