In offline (Cached Exchange) mode, Microsoft Outlook stores all Exchange mailbox data in a local file termed OST file. When the Exchange connection is re-established, the modifications made by the user in offline mode are updated to the server mailbox. Exchange Server failures and catastrophes, Exchange mailbox deletions, and other events have no effect on the OST file because it is stored on the user’s PC. As a result, in the case of a disaster, Exchange administrators and end-users can use OST files to restore user mailbox data.
Scenarios in Which Converting an OST File to a PST File Is Beneficial:
- A small number of Exchange mailboxes are removed from the server.
- A couple of Exchange mailboxes need to be backed up.
- An Exchange user wishes to rebuild his OST file, however, there is some data in the OST file that has not been preserved.
- Due to Exchange corruption, server crashes, and other factors, OST files are unavailable, and users require immediate access to their emails.
If you can log in to Outlook with the same Exchange profile, you can convert any OST file to PST using one of many techniques. Here are several natural techniques for converting OST to PST: