If you're looking for a reliable tool to convert OST files to PST, I highly recommend the OST to PST Converter. It's one of the finest and most efficient utilities out there, ensuring a seamless conversion process without any data loss and maintaining 100% accuracy. This software converts OST to PST and supports various file formats such as MBOX, PDF, and JSON. Additionally, it can export OST items such as Emails, Calendars, Contacts, and Tasks to over 15 different web and cloud-based email clients. It's a robust solution that covers all your OST to PST conversion needs and more.

Converter Tools provides the most efficient tool for converting the OST file to a PST file. OST to PST Converter is an emerging tool that converts OST files into PST file formats, including emails, calendars, tasks, notes, and journals. It offers to change OST files into PDF and other various file formats. The OST Converter Software migrates OST files into Office 365 and other cloud or web-based email clients such as Gmail, Yahoo, IMAP Server, Thunderbird, Hotmail, etc. It is compatible with all Windows versions, including Windows 11.

https://www.convertertools.org/ost-to-pst/