If you manage a number of WordPress sites, you may find yourself inundated with emails each time a new version of WordPress is released. If you’d like to quickly disable these types of notifications, check out Control WP Core Emails, a brand new plugin developed by Andrew Norcross of Reaktiv Studios.
Once activated, browse to Settings > General and scroll to the bottom of the page. From here, you can configure which emails you want to suppress. Email types include, success, manual, failure, and critical. One thing to note is that Control WP Core Emails does not provide the ability to manipulate the emails. Its sole purpose is to disable them from arriving in your inbox.

Norcross created the plugin as he normally receives approximately 100 update emails between local, dev, and production sites. He doesn’t have any plans to extend the plugin as he’s unsure what other functionality it needs. Norcross is open to feedback and if you have suggestions or need to file a bug report, you can do so on the project’s GitHub page.
So if you have 100 sites, then you will need to install the plugin on all the sites, then configure each one of them?