Issue Summary

Security focused business sectors need strict control over the access granted to external users, this means preventing User Access Admins also from sending invites to domains like gmail.com, which at this time cannot be done. This is described in this documentation.

Workaround

There is no workaround possible. At this time Org Admins need to regularly review External user access as they have no way to prevent project Admins from inviting external users.