There are two versions of OWA: light version and the full version. Depending on how it was configured when you first log onto your Exchange account, you may be using the light version of the OWA without knowing it. To check which version of OWA that you are using, look at the Internet Explorer Title Bar or the Tab Bar, if it says "Outlook Web Access Light", then you are using the light version.
To switch OWA from the light version to the full version, click "Options" in the upper right corner, then click "Accessibility" in the left navigation pane.
You'll see that "Use the blind and low version experience" is selected. Check it off, then click "Save" at the top.
You'll see a confirmation message "Saved successfully", click "Log Off" and close the window.
Log in the OWA again, you'll see "Outlook Web Access" in the title bar and tab bar.
Click on "Options" in the upper right corner, you'll see that the full version has a lot more options than the light version.