Summary:

Currently, when Approved domains are added to the system by a site-admin, there is no warning notifying admins of the addition of public domains like gmail.com, outlook.com, etc. These are not corporate domains and are used personally.

Suggestion:

Provide a warning or a pop-up banner every time an admin tries to add a public domain. (like gmail.com, outlook.com)

An oversight here could result in a serious security concern as company data could be revealed to potentially anyone, say with the gmail.com domain.