You do not need to waste your time sending emails and control them. If you want to see the final version of your template please click the Preview button from the top right menu.
Note: Preview shows the final version of your template. If you turn off the replace email functionality, in this case, you will see the default email template. Before checking the Email Preview, make sure that you enable replace email functionality.
More information about enabling/disabling email customizing in Email Customizer: How to enable email customizing?