Email Address Policies

Hi there

I have an Exchange 2013 Std server, which currently has the Default Email Address Policy abc@domain.com.

I'll be incorporating a second domain within Exchange shortly, and need to distinguish users between the Default Email Address Policy -abc@domain.com and a second policy for cba@domain.com.

Creating the second policy is seamless, but it only has an option of applying that policy to all mailboxes.

So the question is, how can I leave the Default Policy in place for users that need to have theabc@domain.com email address only, but still assign thecba@domain.com policy only to other users of my choosing, or, for any new mailboxes created.

Thanks