I have an old OST file from a previous Outlook account, and I’m trying to open it in Outlook on my new computer. Outlook doesn’t seem to recognize the OST file as a normal data file.

Is there any proper way to open OST file in Outlook  when the original Exchange account is no longer available? I mainly need access to my old emails, attachments, and folders.

I came across Advik OST to PST Converter, which can convert OST data into PST format. Since Outlook supports PST files, I’m wondering if converting the OST to PST first would be a better approach.

Has anyone tried this method or used Advik for recovering data from an old OST file?