From those logs it looks like the culprit isn't ISA. You've posted a normal open and normal close. I would take a look at the IIS logs. thanks, Amy Babinchak Harbor Computer Services | 248-850-8616 Mobile 248-890-1794 Web http://www.harborcomputerservices.net<http://www.harborcomputerservices.net/> Client Blog http://smalltechnotes.blogspot.com<http://smalltechnotes.blogspot.com/> Tech Blog http://securesmb.harborcomputerservices.net<http://securesmb.harborcomputerservices.net/> Buy My House: http://www.shannonrealty.com/vassar_mls_tour.html Are you an IT Pro? http://www.thirdtier.net<http://www.thirdtier.net/> From: isalist-bounce@xxxxxxxxxxxxx [mailto:isalist-bounce@xxxxxxxxxxxxx] On Behalf Of William T Holmes Sent: Friday, December 05, 2008 8:59 AM To: isalist@xxxxxxxxxxxxx Subject: [isalist] Access Problem Outlook 2007 Sharepoint Lists to Sharepoint 2007 server through ISA Hello, I have added a sharepoint list to outlook. When I attempt to sync this list I receive the following error on outlook: Task 'SharePoint' reported error (0x8000FFFF) : 'An error occurred either in Outlook or SharePoint. Contact the SharePoint site administrator. HTTP 0.' I started a monitor on the ISA server and this shows: Initiated Connection ISA-FIREWALL 12/5/2008 8:46:01 AM Log type: Firewall service Status: Rule: Source: External (my.client.ip.address:62303) Destination: Local Host (192.168.22.10:443) Protocol: HTTPS User: Additional information Number of bytes sent: 0 Number of bytes received: 0 Processing time: 0 ms Original Client IP: my.client.ip.address Client agent: Closed Connection ISA-FIREWALL 12/5/2008 8:46:13 AM Log type: Firewall service Status: Rule: Source: External (my.client.ip.address:62303) Destination: Local Host (192.168.22.10:443) Protocol: HTTPS User: Additional information Number of bytes sent: 690 Number of bytes received: 2447 Processing time: 11984 ms Original Client IP: my.client.ip.address Client agent: Moving the Outlook Client to an internal network allows the Sharepoint List to Sync. Also from the client I can access the sharepoint server through the ISA server using WebDAV and Via a Web browser. Any ideas on what migh be preventing Outlook from syncing when on the external network? Thanks Bill