Group Calendar Invites

Group Calendar Invites

How do you add an external invitation to an event created in a group calendar?

I have users that are subscribed to a group calendar.

If a user creates a new event in the calendar view, a drop down box allows the user to select which calendar the event will be added to. In this case the user selects a group calendar.

The user can also add the emails of people that she wishes to invite to the event by typing their names in the attendees box.  Some of these may be organizational (eg jimsmith@zoho.com) l, but 1 or more may be external people ( bobgreen@gmail.com).

When saving the event, an error is generated as follows

"Organization Policy does not support to add non-organization members as attendees"


Where can I change this policy?