this email is used for sending the registration email for the Claims Portal , also there are Questions what Username and what kind of coins and balances you got there.
Also where are you from is asked and they can see that from there Ips they got back in the days and there are more things that only the owner can know.
Maybe it's easy for you to remember the exact transactions after all these years but for others like myself, it's not. Neither do I remember the whole amount and which coins I had in exact numbers. You need at least 3 correct matches to different sections to proceed and there is no e-mail to contact them and do this "manually". At least I don't have any but for sure I had funds. So by saying that they really want to give back our money but instead they leave time passing and make things harder, is just a joke.