Here is the way to export OST to PST files, provided by eSoftTools OST to PST Converter Tool. it recovers OST emails, msgs, journals, attachments, deleted files, etc, without any changes or loss. It can convert any large-size OST files. This software is easy to use and users can easily handle this software. It has a fast conversion process during the conversion of OST Outlook. Also, you can see all mailbox items live preview before the conversion.
know more-https://www.esofttools.com/blog/osttopstexport/
know more-https://www.esofttools.com/blog/osttopstexport/