How to enable an AD security group for use with Exchange

By default when you want to use an AD security group within Exchange - lets say for example within a transport rule you will notice that by default they are not available.

So in order to make the security groups accessable we need to 'mail-enable' them: AKA mail enabled security groups. In order to do this we should firstly ensure that the security group's scope is 'Universal' NOT 'Global' as it is by default.

We can then proceed to go to the Exchange Management Console >> Recipient Configuration >> right-hand click 'Distribution Group' >> New Distribution Group >> Select 'Existing Group' >> Next ensure 'Security' is selected for the group type and seelct the relevent security group.

You should now be able to specify your mail enabled security group within Exchange e.g. when creating transport rules.