In my Exchange Server 2007, I've just created a security enabled distribution group with me and some members, I also have checked (put tick box) in the "Send As" attributes from ADUC console.
But how come I always get NDR "You are not allowed to send this message because you are trying to send on behalf of another sender without permission to do so. Please verify that you are sending on behalf of the correct sender, or ask your system administrator to help you get the required permission." ?
I wonder what should I do in order to resolve this issue ?