Step 1 : Create Email template categories.
Go to Marketing -> Emails -> Add a category
Write the name of the category and click on "create" to confirm.
Step 2 : Create/modify a template.
In Marketing-> Emails -> "Create a template" or click on the pencil to modify an existing template
Click on the "Category name" bar, and choose the category associated with the Email.
Your template will then be under the category you have chosen.
Step 3 : Order your mails.
You can also adjust the order of your Emails via the drag and drop available on the left of your template.
For more information regarding other tabs of the marketing emails, go to the Marketing section of the Help Center.”