MimeData FileContents entry is empty when drag&dropping Outlook e-mail

FileContents mime entry is empty when viewing the MimeData of an outlook e-mail that was dropped on to Qt application.

This bug is reproducible using Qt Example program "Drop Site" (http://doc.qt.io/qt-5/qtwidgets-draganddrop-dropsite-example.html).

Steps to reproduce:
1) Start the example program Drop Site.
2) Drag an e-mail from Microsoft Outlook on to the Drop Site program.
3) Check the Mime Data, specifically the FileContents entry.

Expected result:
The file data is contained in FileContents. Attachments of the file are entered with index=x entries.

Observed result:
FileContents is empty. User cannot save the drag&dropped e-mail to a file. E-mail attachments are unreachable.