Today I wanted to create a new Mailbox User over the ECP and the OU list was empty. So I was shocked and a little panic was noticed.
So what has changed?
OUs? Yes, there was some OU’s added last weeks.
So I find the following KB at Microsoft: https://support.microsoft.com/de-de/help/3038717/exchange-server-doesn-t-display-all-ous-when-it-creates-a-new-mailbox
What, Exchange has a default list of 500 for OU’s? Ok, lets change this, because we are now over 500 🙂
- First connect to one of the Exchange Server
- Start Exchange Powershell and get a count of your OU’s
Powershell Command for Count OU’s
(Get OrganizationalUnit-ResultSize unlimited) .count
- Search for the following directory
%systemdrive%:Program Files\Microsoft\Exchange Server\V15\ClientAccess\ecp
- Edit web.config in </appsettings>
Code to add
<!-- allows the OU picker when placing a new mailbox in its designated organizational unit to retrieve all OUs - default value is 500 -->
<add key="GetListDefaultResultSize" value="500" />
- Last step is to Restart an IIS App Pool called
IIS App Pool
Note: The value GetListDefaultResultSize should be greater than the Count of the Powershell Command before and the value must be added every time you install a cummulative update on your Exchange Servers.