Hi Kent,
When scheduling from the MeetingPlace Express web page, the users that you can invite that pop-up are populated from the MeetingPlace Express user database. This is typically populated from the CUCM user database or Active Directory when the users logs into MeetingPlace Express. Make sure these users you want to invite have a MeetingPlace Express profile by going to the MeetingPlace Express web page, Administration, User Configuration, User Profile Management and searching for their username. You can also add users in here manually if you wish.
However if you are inviting users from the Outlook plug-in, when you start to enter a user's email address to invite them, this would be populated directly from Exchange.
If this does not answer your question, try posting an example of the data file you are seeing that is missing users.
Regards,
Andrew
