Resource Mailbox Usage Reporting

Frequent Contributor

Is there a way to report on usage of a resource mailbox?  For example, we have a room and want to know how often it's scheduled for how many people, etc.

3 Replies
Best Response confirmed by Tony Derricott (Frequent Contributor)

Hi @Tony Derricott,


Have a look at this script. I think it will give you what you need.





@Nuno Mota 

I'm getting all the way to the point where I get the following error:

Unable to query Graph API: 'The remote server returned an error: (401) Unauthorized.'

Have tried with my own Global Admin and with


You don't need any special account in Office 365/Azure in order to run the script (actually, just run it with your normal/local account!). What you need to do is go to the Azure management portal (, then go to "App registrations", and click on "New registration". From there, give it a name, create a secret, and in "API permissions" give it the permissions I mention in the script for "Microsoft Graph".

Then, you use the details from the app registration to update the $ClientID, $ClientSecret, and $TenantID properties in the script. This is what the script uses to authenticate against Graph API and retrieve all the information from meeting rooms.