The ability to send to an email address based on an attribute value is a new feature being introduced in AF 2017 R2, estimated to be available by end of the year 2017.
If you need two emails sent to two different people, what you would need to do is configure two notification rules with each one sending different content to different people based on the new feature mentioned above.
Since the 2017 R2 release satisfies your needs, I will go ahead and mark this suggestion "Declined".
