Whilst it is a reasonable request i wonder if users would be more prone to accidentially moving folders...

I understand the user error but nothing stops them from moving them back. 

I agree with Nathan: drag and drop of folders is too dangerous, too many compliants by users that "lost" their email folder by a drag and drop error...

So people are really that stupid? Not to be mean but for real? Then why does Google, Microsoft, and everyone else allow it (desktop and web)? I cannot believe our world is that F'd up that we can't have drag and drop.

John, to answer your question, yes, there really are people that would struggle with it enabled. It sounds crazy but these people exist in greater numbers that you would expect and we would have to deal with the support fallout for things going 'missing' with accidental dragging of folders.

I would be happy for it to be an option but disabled by default.

Option, off by default, would be great. Heck, even better, enable it BY USER and not domain.