Issue: Not able to see outbox in OWA with IE,  if your account is in O365 or if you don't have the option to pick enable the light version of Outlook Web App for the blind and low vision experience.

Solution. Enable Light version of OWA by modifying the url.

Type "/?layout=light" after /owa without the quotes.
Example: the URL now looks like this:
https://mymailserver.mydomain.com/owa/?layout=light