One of my clients had a distribution group for All internal employees. I recently got them to let me convert it to a Dynamic Distribution Group to cut down on administration (lots of tickets from HR to add/remove users to this group).
The Dynamic group currently includes all user mailboxes living in domain\Divisions\Users and subfolders, which includes their OUs for Full Timers and Part Timers, and Disabled Users. I set up the filter to exclude all mailboxes with Exchange Custom Attribute 1 set to "excludeDDG" and applied that to all mailboxes living in \domain\Divisions\Users\Disabled User Accounts.
On their DCs, we have the extended schema for Exchange. I want to know if I can use AD to administrate this filter. I want to set a policy on the disabled users OU that sets MsExchExtensionCustomAttribute1 to the value I want (I'm sure that's possible), because if that maps to Exchange CustomAttribute1 then it exclude them from the dynamic group automatically. Because I asked, and they don't want to move the Org Unit out of Domain\Divisions\Users.
So, in summary, I need help figuring out if AD's msExchExtensionCustomAttribute1 will map to the Exchange CustomAttribute1 so that I can exclude them from the dynamic group via my filter with a Group Policy. If this attribute doesn't map to the Exchange custom attribute I want to use, which one does?