in Outlook 2013, there are Search Options (File - Options - Search) that are different from previous versions of Outlook. By default it it set to "Include results only from: 'Current folder. Current mailbox when searching from the inbox'." Changing that setting to be "Include results only from: 'Current folder' should solve the problem. The issue occurs when you have more than one folder included in search - it will appear to NOT move the email when you drag and drop because the destination is also in the search results. Let me know if that corrects the issue or if you need additional help.