Before days back I was searching for the best tool for converting OST files to PST files, then I got in Google Enstella OST to PST converter software which is the best to work for me and resolve all issues of OST files. The best part of this software you are not satisfied with the software and contact the support team not to assist you then you can take a 30-day money-back guarantee. You can check the official website for complete knowledge about the software. It export mailbox items and import OST files to Office 365, Gmail, Yahoo mail, and Outlook.com webmail. Enstella gives a free demo version and converts 25 items of every folder & subfolder.