When you organize a meeting, you may encounter the following problem: you have two email addresses for a participant, but you don’t know which one they’re currently using. You send the invitation to both email addresses, but this increases the number of participants by two, even though only a single participant is being invited. This may limit your room selection, as the number of participants exceeds the capacity of smaller rooms, leaving you with only rooms that may be too large for your meeting. This article shows you how to work around this issue.
Procedure in Outlook
When creating the meeting, disable the "Automatically determine" option.
Enter the number of participants in the "Number of Participants" field.
The room selection will be limited based on the number of participants.