What is OST (offline Outlook Data File)file?

OST is an Offline Outlook Data file that can’t be opened directly in any Outlook profile or account. . It’s an encrypted file created when you set up an account in Outlook. The file binds to a particular profile and PC on which you have configured your account. However, you can import and open OST mailbox items in Outlook 2019, 2016, 2013, 2010, and 2007 after converting them to Outlook supportable PST format.

Personal Storage Table or PST is also an Outlook data file that you can open and import into your Outlook account.

You can Import outlook mailbox items in the PST format either via Outlook Import/Export wizard or by using a third-party OST converter tool such as Stellar Converter for OST. The software converts inaccessible or orphaned OST files. Further, it can export OST mailbox items directly to the existing outlook profile or new PST file.