Tell me about the issue and I’ll help you find the solution you need.
Exchange Server 2013 doesn't display all OUs when it creates a new mailbox
Content provided by Microsoft
Applies to: Exchange Server 2013 Enterprise, Exchange Server 2013 Service Pack 1, Exchange Server 2013 Standard Edition
When you create a new mailbox together with a new user account in Exchange Server 2013, the complete list of organizational units (OUs) is not displayed as expected.
Exchange Control Panel (ECP) can display no more than 500 OUs. When there are more than 500 OUs, a new window is generated, and this window is either blank or contains a "There are more items to show in this view" message.
To resolve this issue, follow these steps:
Determine the number of OUs on the Exchange Server 2013 mailbox server. To do this, run the following command in a shell: