Today I almost had a 'Cold Sweat' moment.
When you almost click the button, but thankfully some little voice in your head says 'are you sure?'
I needed to remove a mailbox from a user but leave the user intact. The problem is that when you click Remove-Mailbox or use the powershell command to do the same, it removes the mailbox (good) and the AD User (bad).
So... what do ya do? Well thanks to Jeremy Phillips, the answer is the 'Disable-Mailbox' command.
To delete a user’s mailbox but keep the user account, you use the rather unobvious Disable-Mailbox...