If you are using a Microsoft Exchange Server account, all of your email messages and other mailbox items such as: calendar, contacts, tasks, notes, etc. they are sent to the server and saved on it. A local copy of these items can be stored on your computer system in an Outlook data file, which is known as an OST (Offline Storage Table). It is an offline Outlook data file that allows users to work offline or work with their mailbox data even when they are not connected to Exchange Server. Because of this feature, the file is called an Outlook Offline Data File. It automatically syncs with the Exchange computer when the connection to MS Exchange Server is available.
An offline Outlook data file is considered to be a beneficial file format for Outlook users; on the other hand, it also has some negative points. Just like a PST file, it also has some limitations that can create some serious problems. As an Outlook PST file has a size limitation, in the same way, an offline Outlook data file also has a size limitation issue. If the file exceeds its size limit, it may become corrupted or damaged. This is not the only cause of corruption; In fact, there are several reasons that can cause corruption such as: virus attack, hard drive crash, unexpected MS Outlook cancellation, network failure, system power failure, synchronization error, etc.
If the main issue is exceeding the size of an OST file, it can be resolved by setting a sync filter on your Exchange Server mailbox folders. This manual technique helps you reduce the file size without causing any side effects. To perform this technique, the following steps are required:
- Right click on the mailbox folder you want to shrink > click on Properties.
- Tea Properties the dialog box appears. Click on Synchronization table > Filter button.
- Tea Filter the dialog box appears. Now choose the standard for synchronization (set any filters you want).
- Click on okay. Now restart your MS Outlook program.
If you suspect that your offline Outlook data files are corrupted, you can perform an integrity check using SCANOST.EXE. It is very similar to SCANPST.EXE and performs actions in the same way that SCANPST.EXE does. It is used to scan corrupt OST files and determine errors in OST files. If the selected OST file is damaged, it automatically restores the file structure and rebuilds the headers.
SCANOST.EXE can be found in these locations depending on your version of MS Office:
- For 2010: C:Program FilesMicrosoft OfficeOffice14
- For 2007: C:Program FilesMicrosoft OfficeOffice12
- For 2003: C:Program FilesCommon FilesSystemMSMAPIscanost.exe
- For 2002/XP: C:Program FilesCommon FilesSystemMAPIscanost.exe
- For 2000: C:Program FilesCommon FilesSystemMAPINTscanost.exe
Before using this utility, make sure that your MS Outlook program is not running on your system, it must be closed. Go to the location shown above according to your MS Outlook program, and then follow the steps below:
- Place you SCANOST.EXE and double click on it.
- The Microsoft Outlook Inbox Repair Tool window appears on your screen.
- Now select the profile that contains the corrupt OST file.
- Select the appropriate option. check the box “Fix bugs” to solve the problems.
- Click on start scan to start scanning the selected OST file.
- Once the file is scanned and repaired, you get a message that says OST repaired successfully.
Unfortunately, SCANOST.EXE can sometimes fail to repair corrupt OST files. In such a situation, you need third party OST recovery software that can repair your corrupt OST file and get your data back. Since you have no better option than this, you have to check it out. It helps you scan for corrupt OST files and fixes any level of corruption from them. Third-party recovery tools are usually available with a free demo or trial version. You can check them out before purchasing the full version. The demo or trial version allows you to preview the recovered data and helps you examine the software.