An OST file, short for Offline Storage Table, is a data file created by Microsoft Outlook when it is configured to work in an offline or Cached Exchange Mode. Outlook uses OST files to store a copy of the user's mailbox data, including emails, contacts, calendar items, tasks, and other items.

The primary purpose of an OST file is to allow users to access their mailbox data even when they are not connected to the Exchange Server. When Outlook is in offline mode, any changes made to the mailbox, such as creating or deleting emails, are stored in the OST file. These changes are then synchronized with the Exchange Server when the user reconnects to the network.

OST files are particularly useful for users who travel frequently or have intermittent connectivity to the Exchange Server. They provide offline access to emails and other data, allowing users to read, compose, and manage their mailbox even without an active network connection

There can be several reasons why you may be unable to view, open, or read an OST file. Here are a few common causes:

1. Outlook Profile Issues: If the OST file is associated with a specific Outlook profile, it may not open if the profile is corrupt or damaged. In such cases, you may need to recreate the Outlook profile or repair the existing one.

2. Synchronization Problems: If there are synchronization issues between the OST file and the Exchange Server, it can lead to difficulties in opening or reading the file. This can occur due to network problems, server errors, or conflicts with other synchronization processes.

3. File Corruption: OST files can become corrupt due to various reasons such as abrupt system shutdown, software conflicts, malware infections, or storage media issues. When a file is corrupted, Outlook may fail to open it or display its contents correctly.

4. Incompatible Software: If you are using an older version of Outlook or third-party software that is not compatible with the OST file format, you may experience problems opening or reading the file. Ensure that you are using a compatible version of Outlook or software that supports OST files.

5. Access Restrictions: If you do not have the necessary permissions or access rights to the OST file, you may be unable to open or view its contents. Check the file's permissions and make sure you have the appropriate privileges.

6. Deleted or Lost OST File: If the OST file has been accidentally deleted, moved, or lost from its original location, you won't be able to open or read it. In such cases, you may need to restore the file from a backup or use specialized data recovery tools.

Best Way to view an OST file and save in TXT file format

To View the OST file and save it into TXT file format you need to use the Data Recovery Freeware OST Viewer Software. This OST viewer freeware helps to view, open and read OST files with all their data. This OST viewer helps to open view and read OST file whether it is corrupted or healthy OST file. However, this tool maintains the data hierarchy throughout the process. This tool is capable of all versions of OST files.