If you are using a Microsoft Exchange Server account, all your email messages and other mailbox items such as: calendar, contacts, tasks, notes, etc. they are sent to and stored on the server. 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 enables users to work offline or with their mailbox data even when they are not connected to the Exchange Server. Because of this feature, the file is called an offline Outlook data file. Automatically syncs with Exchange computer when connection to MS Exchange Sever is available.
An offline Outlook data file is considered a beneficial file format for Outlook users; on the other hand, it also has some negative points. 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 get corrupted or damaged. This is not the only cause of corruption; in fact, there are various reasons that can cause corruption, such as: virus attacks, hard drive failure, unexpected cancellation of MS Outlook, network failure, system power failure, synchronization error, etc.
If the main problem is exceeding the size of an OST file, then it can be solved by setting a sync filter on your Exchange Server mailbox folders. This technical manual helps you reduce the file size without causing any side effects. The following steps are required to perform this technique:
- Right click on the mailbox folder you want to shrink > click on Properties.
- Tea Properties the dialog box appears. Click on Synchronization tab > Filter button.
- Tea Filter the dialog box appears. Now choose the standard for synchronization (set the filters you want).
- Click on ok. 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. This 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 the 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 according to your version of MS Office:
- For 2010: C: Program Files Microsoft Office Office14
- For 2007: C: Program Files Microsoft Office Office12
- For 2003: C: Program Files Common Files System MSMAPI scanost.exe
- For 2002 / XP: C: Program Files Common Files System MAPI scanost.exe
- For 2000: C: Program Files Common Files SystemMAPI NT scanost.exe
Before using this utility, make sure 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 shown below:
- Locate 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 errors” 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 saying that the OST was successfully repaired.
Unfortunately, SCANOST.EXE may sometimes fail to repair corrupt OST files. In such situation, you need third-party OST recovery software that can repair your corrupted OST file and get your data back. Since you have no other better option than this, you have to check it out. It helps you scan corrupt OST files and fixes any level of corruption in them. Third-party recovery tools are generally available with a free trial or demo version. You can check them out before buying the full version. The demo or trial version allows you to see the preview of the recovered data and helps you to examine the software.
