This works here. But it seems to be search dependent.
If I use the X1 search for Attachments, drag and drop works. Try it from an email search with an attachments column, and all hell breaks loose. Windows Explorer crashes and has to restart. (This is in Windows 7.)
This is for drag and drop to the desktop as well as into an email.
I would expect to be able to drag and drop from the preview pane, but no go.
Looks like a bug to me. I can't believe that X1 has removed this feature.
Oh, and it doesn't always work in X1 6.7 either.