Outlook 2011 - how to disable auto correction?
Changing settings within Outlook didn't help. It appears that Apple has an overriding spell check, and when it's on, Outlook still automatically corrects words not in its dictionary, making them into embarassing spelling mistakes. 

In my version of the Mac OS (10.9.4), the master switch is in:
   - system preferences
     - keyboard
       -text

Other versions of the Mac OS (Lion?) apparently have it in:
   - system preferences
      - Language &amp; text
        - text

Thanks to answers.microsoft.com for pointing me in the right direction.