Using older versions of Outlook for Mac in business environments
While it's inexcusable that MS has not fixed this, I'd still like to point out that you have have two alternatives without leaving Outlook for Mac:
- Use Legacy Outlook, rather than New Outlook. It's not a forever solution, but for now it still works, and probably will continue to work for some time, until they support on-premises Exchange accounts in New Outlook.
- Use the step-by-step I wrote on page 3, and which I've replied to in this post so you can click on it to see it here, on how to change full name for IMAP accounts. (I can't seem to find a way to link directly to the post reply.)