There is an e-mail distribution group (Mail Non-Universal Group) listed in the Distribution Groups on our Exchange Server 2007 that is not found in our Active Directory. I am puzzled as to how that happened and how to fix it (other than re-creating the group). According to what Exchange shows, it should be in the Users OU in AD. This is our only Exchange Server (I moved the mailboxes from Exchange 2003) and the AD schema was updated to Exchange 2007 when installing Exchange 2007, as instructed. I have noticed that if I create a user in AD, that the mailbox doesn't work if also created in AD. It only works if created in Exchange 2007. The same is true for distribution groups. So, I don't know if that means something is wrong with the Exchange setup, though I carefully followed all the instructions I could find from MS about upgrading to Exchange 2007 and about decommissioning the last Exchange 2003 server, and it seems to work fine otherwise. Our AD is Windows Server 2003; we do not have Server 2008 yet.