installation email address not recognized

This is the page that will help you reach Adobe support. We are users like you, so can't do anything to solve this. 

https://helpx.adobe.com/contact.html There is a chat button in the lower right corner. 

~Barb

It may not be relevant; it can be difficult to activate CS6 since the direct activation servers were shut down a year or so ago.

Others may have a more specific answer, but you're going to have to contact Adobe customer support to walk through cancelling your old account and activating the CS6 license, and it may not be that simple.