> And those services also plug the forgotten-password information leak by just informing you "if you have an account, you got an email" instead of giving you an explicit success or error message.
This might be a better approach, but one problem I see with it is: what if the email is not actually delivered because of an internal bug in the website? How would users know they didn't receive an email they were supposed to have received, and take the appropriate action (trying again or contacting help), versus that they entered a wrong or unregistered email?
Email might not be delivered for many reasons that may not all be in control of the sender. It may be classified as spam somewhere along the way. It may simply drop into a black hole. Eventually the user will try again.
This might be a better approach, but one problem I see with it is: what if the email is not actually delivered because of an internal bug in the website? How would users know they didn't receive an email they were supposed to have received, and take the appropriate action (trying again or contacting help), versus that they entered a wrong or unregistered email?