This blog post is meant to show how easy it now is to accomplish this oft heard request in Exchange 2010. Transport rules, introduced with Exchange 2007, provided a lot of new options for administration of mail resulting in even more requests for additional functionality. The rules now have new predicates and actions extending the possibilities of what can be done. For our example, the rule will restrict “Active Directory Mail enabled users” who have their ‘Department‘ defined as ‘Temp Employees‘ from sending mail to the internet, except they must be allowed to send to 2 external domains called: ‘partnerdomain.com‘ and ‘fourthcoffee.com‘. Additionally, to reduce Helpdesk calls, you want to send an NDR when they violate the rule. For demonstration purposes I will use 2 Conditions, one Action and one Exception.
Microsoft Exchange Team Blog will explain you how to do it in Exchange 2010…beautiful blog post..click here
