The customer authorization (provided in the link you clicked) is out of date, and does not entitle you to use the Blended Threat service.
http://track.spe.schoolmessenger.com/f/a/__k1ptlLkUj1tMWW1ORt0A~~/AAAAAQA~/RgRm3HxoP0Q1aHR0cHM6Ly9taWFtaW9oLmVkdS9yZWdpb25hbHMvYWRtaXNzaW9uL2NvbGxlZ2UtZmFpci9XB3NjaG9vbG1CCmT56Ej7ZOKfeR9SIXNvbW1lci5icmFkZHNAd2FycmVuY291bnR5ZXNjLmNvbVgEAAAAAQ~~