For the conversion of OST to PST, you can try OST to PST converter online Software which is an efficient way to migrate OST files to Outlook PST format. Through this third-party tool that smoothly recover corrupt OST files and also export several files into multiple file formats such as-PST, Zimbra, Live Exchange Server, Gmail, Office 365, MBOX, EML, EMLX, MSG, vCard, ICS, and etc. Along with it also show & manage all emails properties or mailbox attachments such as- Show the preview of all OST emails including these items: Messages Attachments Embedded Images HTML Formatting Attachments Header's Details Contacts Calendar Tasks Notes Journal and etc. The software supports all the version of MS Outlook. 

•    Download, install and run OST to PST Converter.
•    Click on the "Open" button to load OST file.
•    There are two options to browse OST file(s).

 Add File: To select OST file one by one.
 Add Folder: To select folder of OST files.

The steps to export the OST files to PST Outlook:
1.    Open Microsoft Outlook.
2.    Click File menu and select 'Open & Export' and click on Import/Export from the available options.
3.    From the Import and Export, click Export to a file and select the file format option – PST from the suggested storage options.

Click here for more info:- https://www.kdetools.com/how-to/convert-ost-to-pst-without-outlook.html

Using Free OST to PST Converter Software all users can recover OST file and convert them into PST outlook file without creating any problem. PDS OST Converter Software allows users to convert OST files into PST, EML, MSG, HTML, PDF, and MBOX. After that it gives you complete authority to re-access outlook OST file. Message filtering option is provided, use and define the dates “from date” to “ to date” between of them you can recover the emails and restore emails by naming convention such as- subject, subject  + date, from and from+ subject and date.

Get Software- https://perfectdatasolutions.quora.com/OST-Converter-Software

OST to PST File Converter tools is highly advanced and recommended by the professional user to use for exporting corrupt OST file data. it maintains the existing folders hierarchy while saving the recovered data. this software also contains interactive preview feature that user's allowed to check the migrated data in the preview pane before saving them.

More Information Click Here.