Ever since I switched to IMAP with Outlook 2011 it has been dreadfully unreliable and has wasted huge amounts of my time.  The latest glitch was when my Inbox suddenly went blank just now, as if there there was nothing in it, whereupon Outlook proceeded to 'download' the contents of my Inbox afresh.  However, when it was finished, all the emails in the Inbox had lost all the colour-coded Categories that I had assigned to them. It will take me ages to reassign them, and they were really rather important. Does anyone know why Outlook is doing this and how I can stop it doing it again?