Can't use my HP ePrint email address

Hello,

I registered my printer, HP Deskjet Ink Advantage 5525 (CZ282C) when I bought it, in December 2012. On 22 June 2013 I registered for HP ePrint and chose the email address veselinmarkovic@hpeprint.com (see screenshot - https://drive.google.com/file/d/0B4Nb74yLObt8SjI0bXB6bmhvdlE/edit?usp=sharing).

However, I can no longer use this email address, as the site recently asked me to reregister and now reports that this address has already been taken.

Can you please help me with this?

Kind regards,

Veselin Markovic