I have recently installed Microsoft Office 2010 over Office 2003. My problem with Outlook 2010 is every message that I receive in Outlook is duplicated. Last night I noticed that there was only 1 copy of each message when I logged on. GREAT! As soon as I connected to the Internet, duplicate messages appeared. My ISP is AT&T and I use Yahoo/AT&T webmail during the day at the office to check my personal e-mail. I leave messages on the webmail server permanently (I think) and I've read this could be the problem. I do this because sometimes messages magically disappear from Outlook; but they always remain somewhere on webmail. Can you tell me how to eliminate the duplicate messages in Outlook? Thanks.