The latest version of Internet Explorer does not support or run Office 365 Education web mail. To solve this you will need to use a different web browser such as Firefox or Chrome.
Solution 2: Check the Clutter folder
Check your Clutter folder. The Clutter folder is found the left panel. If it is not immediately visible, click More. If your missing emails are in the Clutter folder, turning off automatic clutter filtering may resolve the problem.
Solution 3: Check the filter options
Check your Inbox message filter.
Click on the Filter drop down on the top right of your Inbox display.
Make sure All is checked in the Filter section and Date is descending in the Sort by section.
Problem - OWA still opens Office 365 web mail Standard after selecting "Light Version"
Solution: Manually override the display settings
First make sure that you click on Save after choosing the Light version in Settings. Then, sign out and back in to your mailbox.
If Outlook Light still does not open, you may manually force the Light Version to open by clicking one of the links below:
Problem - OWA still opens Office 365 web mail Light after deselecting "Use Light Version"
Solution: Clear the browser's cache
If configuring the settings from inside your Office 365 account does not work, clear your cache and sign in again at the portal. The procedure for clearing your browser cache depends on the browser type: