I have found that Outlook 2003 is not updating folders normally when connected to Exchange 2007 on Windows 2008. The folders eventually update, but it may take several minutes. I'm familiar with how Outlook and Exchange use udp for mail notification updates...and how Outlook will eventually poll on its own (I think). The issue is similiar to what you will see if the firewall is turned on in XP SP2 (without the Outlook exception). You can click send/receive or another folder, and Outlook will update. I have verfied that the firewalls are turned off on both the clients and the 2008 server. Anyone come across this issue yet? By the way, Outlook 2007 works properly. I have also verified that Exchange 2007 mailboxes on Windows 2003 servers work fine.