Impossible setting standard E-Mail-Client

It is importent to set a standard E-Mail App in my automotive Application.
But Windows doen’t allow it. Trying to setting the standard mail app: emClient is not listed:
emClient StandardApp

Windows 10 Enterprise LTSC, Version 1809:
The Version is fix, no update allowed.

What can I do?

Are you sure eM Client has been correctly installed?
If yes, maybe it is a compatibility issue. I see that you are using an older version of LTSC Entreprise (2018!). I’ve been told that compatibility was extended in the latest release (2021, version 21H2). It could potentially explain the problem.

@RauschW

I’ve seen other users who had problems trying to get eM Client installed and working properly with the LTSC Enterprise version. The problem is that it’s not updated anywhere near as regularly as normal Windows so could be missing stuff that’s needed for eM Client. As @Son-of-A-Gun said could be a compatible issue with the LTSC Win version.

Does eM Client even open and work correctly apart from the association problem ?.