Turn off the annoying spell checker in Outlook.

Go to "Options" under the "File" tab and then go to "Mail" at the "Options" dialog box which appears and click "Editor Options..." to get to the "Editor Options" dialog box where you will uncheck: "Check spelling as you type" ...Also uncheck: "Always check spelling before sending" back at the "Options" dialog box. You may not need to do the first half of this at all honestly.