May I know what email you are using? Gmail, yahoo, etc. Because I have experienced that with gmail that there is authorization email as I log in.
But upon checking the 'boxbe waiting list' I saw the confirmation email there. And sometimes it cannot be found there.
Just check the Spam folder of your email, I think it was placed there.
Pretty lately I also am receiving delays in getting these authorization emails lately. So I am usually unable to open my wallet. You just have to wait until blockchain fixes it.
@OP apparently there is no way to switch off this feature. I would suggest to send a message to twitter account of blockchain. Better they answer it themselves.
Avirunes is right, if there is no other way of getting some help then just completely contact the blockhains twitter account or any account that has been owned by blockchain. It may be cause by their servers to have problems issues right now. But with my experience, I am not having problems with their authorization since the last time I logged in, but not maybe this time.