So how do we do this exactly? First, open the Exchange System Console, expand the Recipient Management container and highlight Distribution Group. Either click ‘New Dynamic Distribution Group’ in the Action pane or right click on Distribution Group in the left pane and select ‘New Dynamic Distribution Group’.
Give the Group a name and alias. Click Next.
Click Browse and search for the OU that has the mailboxes you want to apply the disclaimer to. Then select ‘The Following specific type’ and check Users with Exchange Mailboxes. Click Next.
Unless you want to set any other conditions, click Next.
Click New to create the Distribution Group.
Once completed, click finish.
After the group has been created, under Organization Configuration click on Hub Transport, select the Transport Rules tab, and then create the new transport rule.
Give the Rule a name and click Next.
Click ‘People’. Select ‘People’ and browse for the Dynamic Distribution Group that was just created above.
Click on ‘Append Disclaimer Text…” and then enter the text for your disclaimer. Click Next.
Select ‘Execpt when messages are sent to users …’ and then make sure to change it to Inside the Organization. Click Next.
Click New.
Click Fiinish.
Now you have a transport rule based on OU in AD.
