Windows: press `Windows key + .` or `Windows key + ;`
Mac: press `Control + Command + Space`
Outlook on the web: use the emoji picker in the message toolbar if available
Copy an emoji from another app or website and paste it into the email
In Outlook desktop, use `Insert` > `Symbol` > `More Symbols` if an emoji is not available in the picker
On mobile, tap the emoji keyboard on your device while composing an email