Hi,@Steven Sexton
Thanks for posting your question in the Microsoft Q&A forum.
When you configure Microsoft Outlook to connect to Microsoft Exchange, you receive the following error message: Logging on to the Exchange ActiveSync mail server (EAS): server not found.
This problem occurs because Outlook doesn't support connections to a server that's running Exchange Server by using the EAS protocol.
This is the official URL provided by Microsoft: Outlook can't use ActiveSync to connect Exchange - Outlook | Microsoft Learn
If my answer is helpful to you, please mark it as the answer so that other users can refer to it. Thank you for your support and understanding.