I have a registration portal where user inputs his details and then a valid email account.
Currently I check the email is not used already and if it is I reply with the classic: "email already in use" and something like "recover your old password or create a new account with a new email".
I'm wondering how safe it is this behaviour considering I'm giving away the information that the e-mail address which I inserted is actually available.
How can I make it safer? currently I can only think of preventing brute force checks for available addresses but still the problem remains.