Showing posts from September, 2018

Office 365 User unable to book room on-premise in Exchange Hybrid environment

In a federated environment, an Office 365 user was unable to book meeting in room which was on-premise. After tracing the messages created for booking the room, it was confirmed that the message indeed reached but the room was rejecting it for some reason.
The room was rejecting the meeting request as it was considering the Office 365 user as an external user.

So to solve this, we need to run the following command in the On-premise Exchange environment if we want to allow all the rooms:

Get-Mailbox | where {$_.RecipientTypeDetails -like "Roommailbox"}| Get-CalendarProcessing | Set-CalendarProcessing -ProcessExternalMeetingMessages $true

For single room, run the following command:

Get-CalendarProcessing -Identity <Room name> | Set-CalendarProcessing -ProcessExternalMeetingMessages $true 

Now the Office 365 user will be able to book the on-premise meeting room. (This is assuming that the free/busy calendar sharing is already enabled in the federated environment.)