I have also account of Blockchain.info, and  afew month ago I did try to login by used email account. If any account created by using email, should be any way to recover the private key.  But for personal wallet that created without email, the way to login only by private key.  Lost private key for these personal wallet is mean loss the crypto forever, no body can recover it. That why when I created personal wallet, I never forget to write down the private key in several different paper and keep it in several different place too.