Stops outgoing emails that use wp_mail()
The emails are lost forever.
Most likely, this is due to a plugin you have running. There are two different things the plugin could be doing to cause emails to still be sent. 1. The plugin is overriding our overriding of the sending mechanism. 2. The plugin is calling the PHP function mail() directly. Unfortunately in either of these cases, this plugin will not help you.
You can enable logging of stopped emails on the admin menu page Settings > Stop Emails