Hello, I'm troubleshooting a problem with an Exchange 2003 server running in a Windows 2003 domain. There aretwo remotesites connected via a VPN to a third central site. All sites have aDC acting as Global Catalog server. All users are running Windows XP and Office 2003. Several users in the two remote sitesare experiencing delays whensyncing email via Outlook. Outlook will lock upfor a minute or more and sometimes requires a reboot of the PC. Users will see apop-up with the message "Microsoft Office Outlook: Outlook is trying to retrieve data from the Microsoft Exchange Server ..." Sometime this displays the name of theExchange server, sometimes one of the DC's. We have changed the switches to not autonegotiate.We have lowered the MTU settings for the remote users and changed patch cables. We have upgraded the Exchange server and replaced the domain controller in the central location. We have tried cached and online mode for Outlook. No add-ins are running in Outlook and we've even temporarily disabled anti-virus.We've moved the problem users to different computers and different ports on their switch.We have tried forcing Outlook to use the local GC. We have deleted and recreated the inboxes and AD accounts for the problem users. I ran the Exchange troublshooting assistant and EXmon with no real clear indicators of bottlenecks or problem areas. I am smack out of ideas. Anyone have any ideas for what to try next? Thanks for your time.

Hi, Thank you for your contacting Microsoft TechNet Exchange forum. After reading your post, I still have a question may need your clarify. my question is: Whats the outlook mode used, MAPI or ROH(RPC over Http)? Based on the current situation, I still recommend you double check the clients operating system environment carefully. Whether your operating systems enabled some firewalls which may block outlook required RPC ports. For troubleshooting client side issue, I am not sure if you are familiar with netmon trace. Its really a good tool for tracing the process among outlook, Exchange and GC. but the trace log may too big(about 30~100MB). Also, you could enable outlook logging, the ETL log file should be helpful in case you can read and understand it with proper ETL viewer tool. For netmon trace, you can find a lot of article in internet, I include below link: http://blogs.msdn.com/vikas/archive/2008/02/15/howto-take-a-network-monitor-netmon-trace.aspx For enabling Outlook logging, please refer to this article: http://office.microsoft.com/en-us/outlook/HA011742661033.aspx Meanwhile, if you suspect it caused by server side issue, I recommend you also use EXBPA tool for a test since you have tried EXTRA with EXMON without information. At this time, lets try using the EXBPA for both health and connectivity checking. ExBPA can be obtained from: http://www.microsoft.com/downloads/details.aspx?familyid=DBAB201F-4BEE-4943-AC22-E2DDBD258DF3&displaylang=en To run the tool, follow these steps: 1) Install the tool by just clicking Next on the initial screens. Click the Launch button once the installation is complete. 2) Select the Go to Welcome screen option. There is no need to check for updates since you now have the latest version. 3) Choose Select options for a new scan 4) The name of the AD server should be populated. If it is, click the option to continue using the listed GC. Otherwise, enter the name of a GC. 5) Type a label for this scan. Just entering the date would be fine. 6) Leave all of the options at their defaults. The scope should have all servers checked and the type of scan should be Health Check 7) Dont select the Performance Baseline option because that takes 2 hours to complete. 8) Select the speed of the network. 9) Click on the Start Scanning option. 10) The scan will take several minutes to complete. 11) Click on the option to View the Report. Hope it helps. Jason