As you are looking for the process to migrate OST to Office 365, I can recommend you Sysinfo OST to the PST Converter tool based on my own experiences that can provide you varieties of functionality to import OST files into Office 365 as well as other mail clients like; Thunderbird, Gmail, Yahoo, etc. It gives you the option to import data along with attachments as per your requirements with exact accuracy.

OST to PST converter performs several functionalities such as converting OST to PST, CSV, HTML, DOC, EML, EMLX, TXT, PDF, etc. Here, you can get customization to convert the files as per your needs such as a date filter, removing duplicate files, options to convert files along with attachments, and many more.

The first-time user can convert 50 files at free of cost, that’ll help you to know the practical performance and features of the Sysinfo OST to PST Converter.