I dunno about copy/paste; if you try to do that to too many things at once you could pretty quickly suck up resources on the client computer. With OE you can't drag and drop folders (just messages), but with Thunderbird you can even move nested folders; again, I don't know what you can do with Outlook (my friends and I call it LookOut, if that gives you some sense of my desires vis-a-vis Outlook and any computer I control

) I'm not trying to convert everyone to Thunderbird (honest!

) but I have found that for dragging whole folders full of messages from account-to-account it's the easiest program I've used.
Actually Thunderbird has the capability of importing Outlook mail if it's installed on the system. . .at least sometimes. I also found
this thread where someone who had trouble with importing Outlook files imported the pst file into Outlook Express and then imported the mail from OE into Thunderbird.
One warning, HOWEVER you do your imports, be sure that your users, or the Class of Service they're in, have big enough quotas (and message/attachment size quotas) to permit the messages and folders you are trying to import. When I did my original migration, I ran into headaches when a message was too big, or when the folder got full. In neither case did the error in my IMAP client tell me "you idiot, that's too big." It was always some obscure error that made no sense to me. . .
