Modified from a photo by kitty.green66, copyright 2010
https://www.flickr.com/photos/53887959@N07/4984813901

If you manage Exchange for a large organization, you probably dread personnel changes in the central offices. Executives and their assistants are connected to so many projects and resources, it can be very difficult to keep track of them, let alone transfer ownership or access to their successors.

Unfortunately, Exchange doesn’t provide any simple, built in way of tracking and managing resource mailbox delegation. If you (or your predecessor, more likely) were planning ahead, you didn’t assign specific user accounts as delegates. Instead, you added groups to the mailbox Delegates list, and then you added the individual users to those groups. This method is much simpler to manage over the long haul.

If you didn’t, you’re stuck either looking through the Delegates list for each resource or using PowerShell, which would be much quicker. Try this command out:

Get-Mailbox -ResultSize Unlimited -RecipientTypeDetails RoomMailbox,EquipmentMailbox | Get-CalendarProcessing | ?{$_.ResourceDelegates -like “*Identity*”} | Select Identity, @{Name=”Delegates”;Expression={[string]::join(“;”,($_.ResourceDelegates))}} | Out-GridView

Replace Identity, with some unique segment of the person’s Identity. Don’t use their username or email address. You can find the full Identity with this command:

Get-Mailbox <username> | Select Identity

The result should look something like this:

Identity
———
domain.com/Employees/HQ/First M. Last

First M. Last (or just Last, depending on how unique the name is) would be a good choice to use.

This command will give you a grid containing the Identity and the Delegates list of every room and equipment mailbox where the culprit is listed.