Since my migration to Office 365 I’ve been working on cleaning up my domain and removing my Exchange 2003 Server. During the ‘uninstall’ of Exchange 2003 I got an error saying that mailboxes were still connected. Seeing as the server has been off for a few weeks and no one had complained I figured there just had to be an Active Directory hook.
After looking around I found there is an attribute ‘msExchHomeServerName’ that was pointing to my old Exchange server. I cleared it from my user account using ADSI Edit and everything seemed to be working okay. Then the problem came on how to remove it from everyone. I figured Powershell would have something that would work and followed this site, which had the PS command at the bottom. But, my issue was that I didn’t want to set it to anything, I just wanted to clear it. So, after some testing I utilized this command: