In order to use Word as your e-mail editor or use the "Office envelope" feature in any Office application, you need to use the same version of Outlook and Office. If you upgrade Outlook without also upgrading Office, you'll lose these features.
Not sure what the Office envelope is? When you are working in Word, Excel or other Office applications that support it and click on the envelope toolbar button, the window expands to display To, CC and Subject fields. This is the Office envelope. Click the button again to toggle the fields off.