I have Exchange Server 2010 Environment Installed on MS Widnows Server 2008 R2 Environment. MS Outlook 2010 on Client PC. There are alot of MS Outlook disconnection happening on client PC. Server Windows Application logs keep generating errors like Log Name: Application Source: MSExchange ADAccess Date: 7/11/2011 9:57:55 AM Event ID: 2915 Task Category: General Level: Error Keywords: Classic User: N/A Description: Process Microsoft.Exchange.RpcClientAccess.Service.exe (PID=5732). User 'Sid~XXXXX~RCA~false' has gone over budget '100' times for component 'RCA' within a one minute period. Info: 'Policy:DefaultThrottlingPolicy_8634fe26-c569-431b-a4ad-cea946e88195, Parts:CAS:99;'. Threshold value: '100'. Event Xml:Muhammad Mehdi

Outlook addins . 3rd party archiving or BES in use? You are exceeding the default RPC treshhold which isnt normal. You should investigate what is causing this. Temporary workaround is too increase the default values: http://social.technet.microsoft.com/Forums/bg-BG/exchange2010/thread/e743b2b1-1117-421d-9ee4-48a5255b0d34

Hi, Setting the value for a throttling policy to “$Null” on Exchange 2010 can result in the Default value being used; consequently it is best when creating a custom policy to set the value to something other than Null that is high enough to avoid the issue. EXAMPLE: We can set up a new custom throttling policy and apply to this affected user by the following method: 1) Below is an example of a cmdlet that can be run in Exchange Management Shell to create a new throttling policy named ExtendedThrottling: New-ThrottlingPolicy -name ExtendedThrottling 2) Set it RCAMaxConcurrency to an large number for example 100 or higher Set-throttlingpolicy –identity ExtendedThrottling –RCAMaxConcurrency 100(You'd better make it higher than 100) 3) Apply this new policy on affected user: Set-mailbox –identity <affected user alias> -ThrottlingPolicy ExtendedThrottling 4) After you make this change, wait for the Active Directory replication to finish. -By default, the throttling policy should be applied after 15 minutes. -To apply it immediately, restart the "Microsoft Exchange RPC Client Access" service on any (CAS) Client Access Servers. Best Regards!