
The file binds to a particular profile and PC on which you have configured your account. It’s an encrypted file created when you set up an account in Outlook.

OST is an Offline Outlook Data file that can’t be opened directly in any Outlook profile or account. What is OST (offline Outlook Data File)file? By using the software-based method, you can also directly export OST mailbox items to an existing Outlook profile, Live Exchange Server, or Office 365. The software tool also helps you convert orphaned and inaccessible OST files. You can export the OST mailbox data to PST via Outlook Import/Export wizard (if an associated account is available) or by using an OST to PST converter software tool. To open OST (offline Outlook Data File) in Outlook 2019, 2016, or older versions, it’s required to convert the OST file to PST data file. Or you can recreate OST file when needed.

When you add an account, it will be automatically created. Summary: OST (Offline Outlook Data File ) can’t be opened directly in any Outlook profile or account.
