If you want the best and easy solution to convert OST to Office 365 file without any errors so you can try OST to Office 365 Converter Tool. The OST to Office 365 tool works on all versions of Windows. The software offers users the flexibility to transfer data from any version of Outlook. I will recommend you download this OST to Office 365 converter tool. The user can save the OST files into several different formats like Office 365, EML, EMLX, vCard, vCal, MSG, and MBOX, HTML, and etc.