Okay, I know much acclaim has been given to ADModify, so I tried it. For the most part, it did what I wanted it to, but it totally screwed me on 12 users. I actually have to delete their mailboxes and re-enable them. It took their email addresses out completely and left the users with blank data. All the other users were set just fine. That's too much uncertainty for me. So, while ADModify may work flawlessly for everyone else, I can't mark that as the accepted solution.

  1. List Installed Powershell Modules

PS H: > enable-mailbox-identity 'test user'-database 'MBDS01' enable-mailbox: No provisioning handler is installed. At line: 1 char: 1 + enable-mailbox-identity 'test user'-database 'MBDS01' + ~~~~~ + CategoryInfo: InvalidOperation: (:) [Enable-Mailbox], InvalidOperationException + FullyQualifiedErrorId: 819C0AD1, Microsoft.

Handler

I now have 12 users I have to re-create. When I checked the user's mailbox properties and it populated with default data, it also told me there was no primary SMTP address (even after setting the reply address) and it won't let me save it. Everyone else seems fine. Rancy, I went ahead and tried the 'Set-Mailbox' command on the Exchange server for one user.

It worked fine (without credntials). It was obviously a permissions issue at this point.

List Installed Powershell Modules

I'll mark you as the accepted solution. I can't run the full script on the Exchange server because it is running 2008 SP2 and not R2. So, I can't access the AD module. I'll just take the user list I have, put it in Excel, and fill-down. Then all I'll have to do is cut-and-paste from the Exchange PS on the server. Thank you everyone for the help.