Article ID: 2526306 - View products that this article applies to.
When synchronization issues occur in Microsoft Outlook or in Microsoft Outlook Web App (formerly Outlook Web Access), you may experience the following symptoms.
You see differences or mismatches between the messages that you receive in Microsoft Office Outlook 2003, in Microsoft Office Outlook 2007, or in Microsoft Outlook 2010 compared to Microsoft Outlook Web App.
You have an issue with Outlook, but the issue does not occur when cached mode is disabled.
Occasionally you receive error messages when you synchronize your Offline Folder file (.ost) in Outlook with your mailbox on a server that is running Microsoft Exchange Server.
You notice that some items such as email messages, appointments, contacts, tasks, journal entries, notes, posted items, and documents are missing from your .ost file or from your mailbox after you synchronize your .ost file and your mailbox.
When these symptoms occur, or you have other problems synchronizing, the problem might be a corrupted .ost file.
Outlook 2003 and Outlook 2007
Use the OST Integrity Check Tool (Scanost.exe) to check your .ost file for inconsistencies.
The OST Integrity Check Tool (scanost.exe) is not included in Outlook 2010. This tool was recommended in earlier versions to fix errors in Outlook data files (.ost). If there is an issue with a specific folder, you can resync the folder in Outlook 2010. To do this, follow these steps:
However, the exception is if you have local data that is not present on the server. In that case, we recommend that you follow these steps:
The OST Integrity Check Tool runs only on .ost files and can be used to diagnose and repair synchronization issues. It scans your local copy of the .ost file and your mailbox on an Exchange Server. The tool compares items and folders in the file and in your mailbox and tries to reconcile synchronization differences between the files and the mailbox. The OST Integrity Check Tool does not change your mailbox on the Exchange Server. The tool records any differences in a scan log so that you can see what differences the tool found and resolved. The scan log also identifies any situations that the tool could not resolve and that you must fix manually. The scan log is in your Deleted Items folder.
The OST Integrity Check Tool (Scanost.exe) is installed when you install Outlook in the following locations, as appropriate for the Outlook version that you are running.
For Outlook 2003: drive:\Program Files\Common Files\System\MSMAPI\LocaleID folder. Be aware that in this example, LocaleID is the locale identifier (LCID) for the installation of Microsoft Office. The LCID for English - United States is 1033.
For Outlook 2007: drive:\Program Files\Microsoft Office\OFFICE12
How to repair errors by using Scanost.exe
If you have problems when you try to open your .ost file, you can use the Inbox Repair tool (Scanpst.exe) to diagnose and repair errors in your .ost file. The Inbox Repair tool can be used on both .ost files and on Personal Folders (.pst) files. The Inbox Repair tool scans the .ost or .pst file and makes sure that the file structure is intact. The tool also tries to repair the internal data structures, if it is necessary. The tool does not interact with your mailbox on the Exchange Server.
How to rebuild the .ost file
Article ID: 2526306 - Last Review: October 3, 2011 - Revision: 4.0