AutoCorrect in Outlook

Outlook's AutoCorrect features not only fixes common misspelling, typos and keyboard accidents, but also changes certain combinations of keystrokes into faces and arrows.  Best of all you can add your own special combos to spice up our emails, perhaps adding some greek like π or Ω.  

https://support.office.com/en-us/article/choose-autocorrect-options-for-capitalization-spelling-and-symbols-e7433b94-f3de-4532-9dc8-b29063a96e1f