How can I get Outlook to stop capitalizing i.e.? 

I want to keep AutoCorrect on, and I want to keep Capitalize first letter of sentences turned on. 

I have tried to create an AutoCorrect entry for "I.e." to "i.e.", but it doesn't seem to permit it. I have also tried to create an "INitial CAps" exception for I.e. but it also doesn't work. 

Is there any way to keep the main functionality working but stop this very irritating problem? 

Thanks