Consider the following scenario:
- Some Microsoft Outlook clients connect to a Client Access server array by using a hardware load balancer in a Microsoft Exchange Server 2010 environment.
- One of the Mailbox servers freezes.
In this scenario, all the threads of the RPC Client Access service (RPCClientAccess.exe) on all Client Access servers in an Active Directory site display a pending status. Eventually, the threads become exhausted. Additionally, users cannot access their mailboxes in their Outlook clients.