Wednesday, February 8, 2012

Resolving Outlook OST accessibility issues owing to RPC Connectivity

Microsoft Exchange Server creates OST files in the cached mode that are the exact replicas of server mailboxes but are stored on a user's local computer. These OST files need to synchronize with the Exchange Server in order to reflect all the work done in the offline mode on the actual server mailboxes. Sometimes when the OST file is tried to be accessed it returns the following error message:

The name could not be resolved. The Microsoft Exchange address book was unable to logon to the Microsoft Exchange Server computer.

Root of the problem:

The aforestated error is the result of one or more missing/corrupt RPC registry entries. RPCs (Remote Procedure Call) protocol registry keys are deployed by Microsoft Outlook to make calls to the network. RPCs permit users to send calls to many different protocol stacks, the most common one being TCP/IP. If one or more of these registry keys are missing, Outlook fails to establish a connection with the Exchange Server. Moreover, in the absence of required RPC entries Exchange Services are not registered to respond to client requests.


To identify and troubleshoot the RPC issues RPC Dump can be used. The three most essential RPC components required by Outlook to connect successfully are:

1.The endpoint mapper
2.Exchange Information Store service with the Universal Unique Identifier (UUID) of a4f1db00-ca47-1067-b31e-00dd010662da.
3.The Name Service Provider Interface (NSPI) with the UUID of f5cc5a18-4264-101a-8c59-08002b2f8426.

RPC Dump should be run through the following command prompts:

rpcdump.exe /i > rpcdump.txt
rpcdump.exe /p > rpcdump.txt

In order to restore the missing RPC registry values follow these steps:

1.Verify registry entries
2.Verify the version of the DLL file
3.Remove and reinstall TCP/IP

If this is still not able to resolve the issue, then the OST file has become corrupt and needs to be recovered by OST to PST Conversion. Myriad OST errors are encountered owing to corrupt or orphaned Outlook OST files. The only way for efficacious Outlook OST Recovery is through reliable third party tools. One such sought after tool is “Stellar Phoenix OST to PST Converter”.

Stellar is a leading name in the world of data recovery and this powerful utility can recover all the Outlook OST file data into an importable PST file for MS Outlook 2010, 2007, 2003, 2002 and 2000. The demo version of the software is available for free download and offers a clear preview of the recoverable items in a three view structure. This is an adroit tool that can recover vital user mailbox data by successful conversion from OST to PST.