Overnight on Monday 26 September your email will migrate to the live@edu service, one of the Microsoft Live suite of services.
Email will be shut down during the transition, until the morning of Tuesday 27 September.
When you select email after that, your first login will take a little time while your account is activated. Because this is a Windows Live service, it will give an error if you are already logged in to another Live service, such as Hotmail.
Read up on it at www.flinders.edu.au/studentemail