After searching through many online OST to PST converters, I came across GoldyTools OST to PST File Converter, and I must say—it’s an excellent tool for bulk file conversion. The features it offers are highly impressive and user-friendly.

Key Features of GoldyTools OST to PST Converter:

Quickly Scans Corrupted Files – Efficiently scans and repairs damaged OST files.

Bulk Data Conversion – Supports the conversion of emails, contacts, calendars, notes, and journals in large volumes.

Supports All File Types – Allows conversion of various OST file types into a consistent format.

Multiple Export Options – Lets you save files in multiple formats such as EML, EMLX, PST, HTML, MSG, VCF, ICS, and more.

Single and Bulk File Conversion – Offers flexibility to convert individual files or multiple files in bulk.

The application is very easy to use and requires just a few clicks to get started. Best of all, it provides a free trial version so users can explore all its features before purchasing.
https://www.goldytools.com/blog/how-manually-convert-ost-to-pst-files-in-outlook/