This document describes the deletion of DKIM keys in Email Security.cloud.
Email Security.cloud
Instructions on deleting the DKIM keys in Email Security.cloud.
Navigate to Dashboard > Services > Email Services > Outbound DKIM Signing Settings.
You can see it is impossible to delete all the keys even if DKIM is disabled for the domain. This was by ESS design.
The issue was that we validate that you cannot delete an active selector and when you have only one selector it is automatically the active one since the selection for this is a radio button (one has to be marked active).