If you need you can temporarily stop all outgoing emails from your WordPress site (there are a lot of reasons). Stop Emails is the new WordPress plugin that silently stops all outgoing emails from your website.
Installation & Usage: Install and activate Stop Emails. After the plugin is activated, any outgoing emails will silently fail i.e. WordPress will operate as if the emails were sent successfully but no email will actually get delivered.
In active mode Stop Emails plugin displays a warning message in the backend of your website.