If you want to export Outlook OST file to PST, the easiest and safest way is to use eSoftTools OST to PST Converter software. This tool scans orphaned, damaged or inaccessible OST file and recovers its complete mailbox data like emails, contacts, calendar and attachments. Install the software, select the OST file, then run the scanning process and view the preview. Then start the conversion by choosing PST format in the export option. Once the conversion is complete, you can easily access the generated PST file by importing it into Microsoft Outlook without any data loss.

Read More:- Export Outlook OST to PST