​TL;DR version - Is it possible to save an email to the C: with email metadata available for easy use?

This seems like it should have an easy solution, but I've been stumped so far.

I use Outlook for an email account. I'd like to store some emails outside the .PST file, filed together with other related files (word docs, spreadsheets and .PDFs mainly). It's easy enough to save or ​drag and drop emails from ​O​utlook to an ordinary folder  on the C:. Emails saved/copied/moved this way aren't that usable for subsequent reference though. The subject line of the email becomes the file name, but other metadata (in particular, the email fields like sender, recipient, sent date etc.) isn't there. In Outlook, I search and sort on this information all the time. Windows Explorer even includes metadata tags / file properties / column choices for this email information (I'm not sure of the proper terminology for this, and this might be one of the reasons I am struggling to find an answer). The problem is that Outlook's default .MSG file format doesn't populate this metadata. I've tried all the other Outlook file formats with the same result.

I've also tried other email progra​m​s that save emails in different file formats. It seems that .EML files do populate email metadata / file properties anticipated by the Windows Explorer columns. Of course, Outlook won't save emails in the .EML format (however Outlook 2013 does seem to open .EML files).

What I'd like to do is either populate the ​email metadata / file properties for .MSG files, or save Outlook emails in the .EML file format. I've found a couple of commercial solutions that adopt one of these solutions or the other, but aren't ideal. One option (MessageSave) modifies the existing .MSG metadata. So, for example, the date modified appearing in Windows Explorer is modified to the date the email was sent. My concern with this approach is that it is pretty easy to re-modify the "date modified" information. The other option converts .MSG to .EML. However, all the commercial solutions seem to be focused on some kind of mass conversion (either moving email systems, or for the purposes of legal discovery or audit) For example, SysTools Outlook Conversion. But the tools available under this approach seem much more comprehensive than I need. For example, outputting entire folder trees. So while I don't mind paying for an off-the-shelf solution, I'd prefer one that was a bit more targeted at what I'd like to do.

Any suggestions?