In a LAN ,I have an exchange server 2003 on an additional server 2003 domain controller.Because of some problems I had just one DNS on my first DC and not on the additional one.recently some ofclientssay that their outlookstarts in off line mode . when I delete their computer from domain and add them to domain again it works online for some hours and again becomes offline. at the same time some of these computers but not all ,lose their sharing security property relation with server,and they can not add other users to their sharing ,I added another domain controller to the domainto have anotherDNS ,just forone day everything worked properlythen outlook and sharing problems started again . what can I do ?

Sholeh, I dont think Exchange is a primary culprit here. I would recommend you checking your Active Directory health before you troubleshoot on Exchange Server part. For more assistance on AD troubleshooting you can also post at windows server forums. Howerver, on exchange side I would recommend you following:1. Is there any scheduled job that runs on Exchange at the time of disconnections?2. Can Exchange read the required information from active directory? (you can run dcdiag /v and netdiag from exchange server at that time)3. Running dcdiag from the affected client computers can also help to determine a problem place.4. Check if clients can resolve directory servers and exchange servers correctly.MMilind Naphade | MCTS:M | http://www.msexchangegeek.com

Hi,It seems that is the server issue. Please first ensure the computer is running under the domain. I suspect that the connection between the computer and the DC is not normal.As Milind suggested, you could first post it on the Windows Server forum as below link:http://www.microsoft.com/communities/newsgroups/default.mspxThanksAllen