Outlook prompt dialog for Exchange response 456

Hi,

When Exchange server response http 456, seems Outlook will pick the Status-Line display inside the prompt dialog, see attachment.

However, it is just display in plain text, neither trim HTTP-Version Status-Code, nor decode rfc2047 character which rfc2616 support.

I have tried Outlook for Mac 2016 and recently version from Apple App Store.

Is there a way or plan to improve this?