We have an odd problem where occasionally an e-mail will be found at the root of one of our public folders. These are not mail-enabled folders, these are simply the folder root for contacts or calendars below them. There does not seem to be a pattern. They are from several different people, both internal and even a couple external. They are all unread, so I don't believe they were put there on purpose. They also have valid recipients, so it's not like they just got lost or something. Any ideas why this would happen?