Most likely they know who paid for the address. I need to check if payment via credit card was an option in 2009 or SEPA only. IIRC, the gmx.com address was re

Most likely they know who paid for the address. I need to check if payment via credit card was an option in 2009 or SEPA only. IIRC, the gmx.com address was registered again later by someone else.