Dear Sir or Madam, My company is using Exchange 2003. We have found that we can't download an updated Offline Address Book to Outlook (in cached exchange mode). Then I check the server. I have found the following error. MSExchangeSA error (Event ID: 9300) Description: Failed to generate offline Address Book, error 'c0072030' Please kindly suggest how to solve this problem. Thanks a lot

You should increase OAB logging and try generating the OAB again. Ususally this will point to the problem. One thing that you can look at though is to make sure that the server that generates the OAB has access to the public folder that holds the OAB. An excellent list of ways to troubleshoot OAB problems can be found here: http://blogs.msdn.com/dgoldman/archive/2007/07/06/exchange-server-2003-offline-address-book-best-practices-guide-resources.aspx