Hello Tim, and thanks for getting this posted. While I've not yet tested this personally (plan on doing so in the morning when I get back to the office) I did find recently that the Emojis will fail to encode or display properly unless the user's encoding settings are configured for UTF-8/Unicode, and it looks like Emojis require those encoding types to work as expected. Can you try checking the encoding settings in Outlook and within the user's account and let us know what you find out? Thanks Tim!

I tried that, the user's encoding is set to UTF-8 on both the sender and recipient.