The requirements for someone to set up a Meeting Workspace and send the associated meeting request on your behalf are:
How it works
When your delegate or the person sharing your calendar creates a new or links to an existing Meeting Workspace on your behalf, they are automatically added as a user in the workspace and assigned to the Administrator site group. However, that person is not added to the Attendees list.
In addition, when they create new workspaces, you are automatically added as a user in the workspace and assigned to the Administrator and Contributor site groups, and you are added to the Attendees list.
Note For existing Meeting Workspaces, this information was added at the time you created the workspace.
Once the meeting request is sent, the meeting is automatically added to your Calendar. You or the person working on your behalf can update the request. The updated information will be sent to the workspace when you send the updated meeting request to the invitees. Responses that recipients send will go directly to the Inbox of the person working on your behalf.
If you want to change delegates later, you need to give the appropriate rights to the new delegate. If you want to prevent the previous delegate from accessing the workspace, you must delete their rights on the Web sites.