Your project comes with a system-defined "catch-all" workflow - "All attributes and users" - and has a standard setup:
selecting the first item in your available lists
sending an email for all available case transitions
Tip: While it may be tempting to just use this system-provided workflow, it will not give you much control over how your users manage cases. It should therefore only be used as a quick way to get started; in most cases you will want to create your own custom Workflow.
Note: This default workflow cannot be deleted.
Notifications Override
From the Workflow list, you can temporarily suspend all case email (and push) notifications.
This can be useful if you are modifying your workflows and do not want any email notifications to be sent before you have completed the modifications.
If notifications have been suspended, you can decide what you would like to do with any queued notifications: