Thank you for reaching out to us here on the Community page, @james67.
This error happens if your Outlook profile is corrupted. To resolve the problem, I suggest creating a new profile and check if it fixes the issue. Also, you can fix the Outlook connection by repairing your profile. This helps diagnose and resolves several Outlook issues.
In case you have questions about missing Outlook in QuickBooks Desktop, read this article.
Post again if you have any other questions. I'm always here to help. Have a good day!