We are currently experiencing delays with our email service, which may affect logins and notifications. We sincerely apologize for the inconvenience and appreciate your patience while we work to resolve the issue.
I'm afraid you'd need to turn to a professional repair service in order to determine this. Unfortunately, it could be anything as the drop could have damaged one or more hardware components. I'd recommend you to go to such a service shop and let the tech guys there do a full computer diagnostics.