FileExtensionContentTypeProvider returns no content type for .msg files

[rd-botan-kansiray]

Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

I’m trying to make an API call to upload a .msg file (Outlook email file). To dynamically set the Content-Type header, I’m using the FileExtensionContentTypeProvider from Microsoft.AspNetCore.StaticFiles. However, it returns false for .msg files, meaning no MIME type is found.

Describe the solution you'd like

I would like the .msg file extension to be included in the default mappings of FileExtensionContentTypeProvider, with the MIME type application/vnd.ms-outlook. This would allow developers to handle .msg files more seamlessly when setting content types dynamically, without needing to manually add the mapping.

Additional context

No response

[BrennanConroy]

This is not something we're interested in adding to the defaults. See #31407 (comment)