So, your email isn't working quite right today? Provided that the usual "wait and try again" method doesn't work, then you may need to clear cookies and cache for your browser. Follow the steps below to clear the offending cookies!!
STEP 1: Tools > Delete Browsing History...
STEP 2: Delete files... Delete cookies...
Press the buttons to delete Temporary Internet Files and Cookies. Somewhere in these files is the root of your problem.
NOTE: Deleting anything else may mean that you will lose passwords or History, but, since this is a school computer, it shouldn't matter. Pressing the Delete all... button above will clear everything.
STEP 3: Close Internet Explorer
STEP 4: Re-open Webmail
This should resolve your issue. If it doesn't, this means something else is wrong. Contact the help desk at (919) 664-5700 and let them know what your issue is. Hopefully they can reset things for you. :)