We have been running Exchange SP1 Update Rollup 6 now for some time. I was doing some reading in my Exchange book and came across a section on System and Discovery Mailboxes. There are 4 mailboxes and the user accounts get created in the root Domain. I did check and the accounts are there and disabled like they should be. However, when I try to display the mailboxes using PowerShell on Exchange, nothing comes back. A get-mailbox -Arbitration produces nothing. The Discovery Search Mailbox shows up in the GUI just like any other recipient but I can't display it in PowerShell using the Display name or alias. I just get an error saying the mailbox is not found.
I will tell you that I can and have been doing Discovery searches right along with no issues. I don't think these mailboxes were deleted because we have been running like this for at least a year with no issues at all. Is there a situation where these mailboxes just won't display to keep you from deleting them? I know you can recreate the arbitration mailboxes but I don't want to do that if they are already there and I am just not viewing them correctly.