I would like to suggest you can use
VOOK OST to PDF Converter. This fine feature will help you to
convert & print multiple OST files to PDF at a single time. It is capable to save all the email data of OST file like email messages, attachments, contacts, notes, drafts, and other data items into PDF file format. It can smoothly download and installed on all the available versions of Windows i.e. Windows 2016, 2013, 2013, 2010, etc.
Demo Version of the utility is absolutely free to export OST files to PDF format. It offers users to select the OST file from the system and convert the 25 mails from the selected OST file and convert them in PDF files.
Download and use it now:-
https://vooksoftware.com/ost-to-pdf/