The Active Directory endpoint you're working with has Microsoft Exchange enabled but the MS Exchange tab in Provisioning Manager is grayed out and cannot be edited.
The tab will look like this:
<Please see attached file for image>
Please ensure that you have the appropriate permissions assigned to your endpoint account.
In order to manage and create mailboxes, the account used in the connector must have the following permissions granted:
The Exchange Recipient Administrator role - (without this permission, the Exchange General tab will look like the above screenshot)
The Exchange Server Administrator role on all the mailbox servers
The Local Administrators group on all the mailbox servers and the CCS machine
More information regarding endpoint account permissions and managing MS Exchange objects can be found on our connector wiki.