In an organization having networking environment, numerous outlook users are connected with an Exchange domain server. Microsoft Exchange server links those Outlook user mailboxes with internet in order to establish a reliable environment for all incoming and outgoing emails. When Outlook mailbox of Exchange Server goes in offline mode, a temporary folder or OST file is created in the Windows drive of local client.
OST files are special type of files that allow outlook users to communicate within a domain network when there is no connection between MS Outlook and Exchange server. The changes done in the OST files are automatically transferred to Exchange server when connection gets re-established within the network.
A proper synchronization of Outlook OST files with the Exchange server files is necessary for performing an appropriate email communication. In fact, these offline storage table files are temporary files and visible only for limited duration. Unfortunately, when an internet service gets interrupted for very long time duration, then Outlook OST files become inaccessible. As a result, all user mailboxes stored in these files also get locked for any further use. In this situation, the inaccessible OST files are called as orphaned because they are out of order. Apart from that, the OST files become corrupt or damaged due to various reasons.
Many Outlook users come across different error messages while synchronizing their Offline Folder file (.OST) in Microsoft Outlook mailbox on a Microsoft Exchange Server. Users may also observe that some email items are missing from their .OST file or from mailbox after completing the synchronization process of .OST file and mailbox. In such cases, you should use the OST Integrity Check Tool (Scanost.exe) to check your .OST file. The Outlook .OST Integrity Check Tool runs only on .OST files and can be used to analyze and repair .OST file synchronization issues. It scans your .OST file and your mailbox on an Exchange server, comparing email items. It is a free utility to reconcile synchronization differences between your mailbox on the Exchange server and your local copy of the .OST file.
The Integrity check tool doesn’t change your mailbox on the Exchange server. The tool records any differences in a scan log so that you can see any inconsistency and resolve if any. If you have problems opening your .OST file, then you can use the Inbox Repair tool (Scanpst.exe) to analyze and repair errors in your .OST file. The Inbox Repair tool (Scanpst.exe) can be used on both .OST and .PST files. In fact, it makes sure that the file structure of .OST & .PST is intact and it does not interact with your mailbox on the Exchange server in any way.
In spite of that, if are not satisfied with the final result offered by such utilities, then in such case you should look for a third party OST Recovery utility. It thoroughly scans the corrupt, inaccessible or damaged .OST file and effectively recovers the entire email message with other associated items. On the completion of .OST file scanning process, the tool displays all the recovered email items such as images, notes, appointments, attachments, contact address, task list, etc in a hierarchical structure. Using such tool, you could also save them in .PST, .EML and .MSG file format at the desired safe location.