Is there a way to disable sending emails via the REST API through code?

In my case, when I make a snapshot of my live site to staging (in this case WP Engine), I can then detect I'm on a staging URL, and send automated emails through the site to a test SMTP server (in this case mailtrap.io).

If I forget this then user accounts on my site will start to get automated emails through the staging site (purchase renewal reminders, etc).

If there was simply a way to disable sending emails with this plugin (like unchecking the "Enable" checkbox in the settings does) without having to deactivate the entire plugin that would be ideal.

Thanks!