I am testing 2.1.0-rc.1
When placing an order and opting to pay by Authorize.Net you can enter a billing address if this is different from the delivery address. Once the sale has gone through you receive an email from Authorize.Net "Merchant Email Receipt". The email is showing the billing and shipping addresses to be the same although I entered a different billing address.
I am using a sanbox test account but the results are meant to be the same as a live account so you can thoroughly test all features.
It looks as though to billing address may not been sent through when the sale is processed.