An OST file is an offline copy of your mailbox stored on your local computer. It synchronizes with the email server when you reconnect. Without a live connection to the original server, you cannot open or export an OST file directly in Outlook.
Recover, Export, and Backup Your Outlook Data Without Limits Introduction
Choose a reputable tool, test it on a backup copy of your OST, and keep your Outlook data portable and protected. Leave a comment with your Outlook version and mailbox size, and we’ll help you pick the best converter.
An OST to PST converter extracts emails, contacts, calendars, tasks, and notes from an inaccessible OST file and saves them into a portable, universally readable PST format. A PST file can be opened in any Outlook profile or imported into a new email client.
If you use Microsoft Outlook in a corporate environment, you’ve likely come across two file types: OST (Offline Storage Table) and PST (Personal Storage Table). While OST files allow you to work offline, they are tied to a specific Exchange or Office 365 account. When that account becomes inaccessible—due to termination, server failure, or corruption—your OST data can feel locked away forever.