The Big Brains exam board has produced a website that allows students to access revision videos.
The exam board wants to limit access to those students with a school email account (i.e. one ending .sch.uk). When students sign up JavaScript is used to check that the email address they have entered is from a school account. The address is checked again when it reaches the server before login details are sent to the address.
Explain why it is important to check the email address with JavaScript and again when it reaches the server.