Hi joesaswic,
The only instance in which you would receive an email from Auctiva if you are not an Auctiva is if you purchase an item from an Auctiva user who is using Auctiva's automatic email functionality. In that case, your email address would be provided through eBay's API for purposes directly related to that transaction.
I will post again to this thread when I have additional information on when the "Thank you Bidder" email account setting will be in place.
-Mike