Email adress issues

When i first signed up, it was with my FB account, and for that one i had used a really old email adress, now i changed that adress on my fb but it still exists on this profile of teach away, no matter how i tried to change it here as well, i still can't find the button for it, any way on how to delete it?

ps : it's because i lost that email account looong ago, i no longer use it, and this site's messages will be sent in there.