This article shows you the steps for how you can disable (and re-enable) an email template.
Step One: Navigate to the email settings
From the global navigation select 'Settings'
From here you should now be able to select 'Email' from the left-hand menu:
Step Two: Select 'Templates'
Scroll to the bottom of the page, and select the 'Templates' Button
Step Three: Select the template
From the drop-down menu, select the template that you wish to disable.
Step Four: Disable Template
You can now scroll down and select the disable button. The template will now be disabled and will not be sent to users. If the template is already disabled you will see the option to 'Enabled' the template instead.