Hello,
I own a license that I have purchased through themeforest.net and was used for a site that never went into production (bpcpoland.com - domain expired so I no longer have an access to any mailbox on that domain).
I have tried to register the license no. under my main account but it says that license cannot be registered.
So my question is: how can I now register it to my main account?.. or at least know under which e-mail address was it registered so I can log in to that account (as I have tried every address that was valid at the time for the bpcpoland.com domain but nothing works). Can provide proof of ownership of this license.
… or is it lost for ever? 
Kind Regards,
Filip
