You don't need to know your old email. You just need to sign a message with a Bitcoin address or PGP key associated with the account and send it to theymos or Cyrus[1].
Can you sign a message with one of those altcoin addresses (if you still own any of them)?
LCVMBA375BTrWP93bTgx81h9mZmAWu7hN9 -
this post1CRKdpoPHD9PM9DXhV99ajJXZfd5SXrNSC -
this post
[1] from the post linked above:
If you want us to recover a hacked/lost account, you need to prove that you own it. Typically, the only acceptable method of proving ownership is by signing a message (including current date and desired new email address) using a Bitcoin address or PGP key associated with the account. A Bitcoin address or PGP key is associated with the account only if the account posted the key/address, sent it in a PM, or if it is still listed in the account's profile.