we are using microsoft EBS 2008 and also we have TMG forefriend ,the outlook shows "connectivity to the microsoft exchange server unavailable",how to fix this problem?

Muhammed, Do you mean SBS 2008 with TMG Forefront Protection for Exchange or Forefront client protection? Are all of your appropriate services started? Are your stores mounted? Confirm all of your automatic services are Started, especially your Exchange services. Also, did you disable IPv6 on the SBS server? If so you need to re-enable it or properly disable it through the registry. Can the client that can't connect ping the SBS server? Can that machine browse shares on the SBS? Can you get to OWA from that Machine? You'll need to provide more information in order for us to assist you in troubleshooting the issue. Thanks, Jorge Jorge R. Diaz PMP, CCNA, MCSE, MCSA Sr. Microsoft Consultant Planet Technologies, Inc.

Hi, Did you tried out this link: http://support.microsoft.com/kb/913843Regards from www.windowsadmin.info

Is this happening for internal client or external. is basic network settings are fine, please check event logs and provide little more info.Best Rgds, Ashish | Unified Comunication | MCTS | Please remember to select option "Propose As Answer" if solution work for you.

Hi Muhammed, Any update for your issue, please confirm that publish the SBS 2008 through TMG successfully, and the CERT corrctly issued. Some information for you: http://technet.microsoft.com/en-us/library/bb794751.aspx Although about ISA, same as TMG. Regards! GavinPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.