Hi, Here is our environment in a nutshell DAG with 8 nodes ( exchange 2010 SP2) 3 CAS servers forming an array with a FDQN client.domain.net sitting behind a HW load balancer Users use a mixed of outlook 2003 and outlook 2010. Once in a while users complain of slow outlook. When checking their oultook status we see sometimes high avg reponse from mail or from directory serviced by the FQDN of the array. The numbers of aver reponse vary from 10 to sometimes 50 sometimes more. The question we have is what numbers or thresholds are acceptable beyond with we shoud start looking at performance issues? I know it's a vague question but maybe someone has an insight. Thanks

Take a look here: Performance and Scalability Counters and Thresholds http://technet.microsoft.com/en-us/library/dd335215.aspxMCTS: Messaging | MCSE: S+M

Hi 1. You can run Outlook in Safe Mode to troubleshoot the issue. 2. This is KB of it. Folders take a long time to update when an Exchange Server 2010 user uses Outlook 2003 in online mode 3.You can run exbpa on exchange 2010 and find clue of your issue. Terence Yu TechNet Community Support

Thanks