Here I can recommend one more amazing OST to Office 365 migration tool that helps to transfer a bunch of  OST files to Office 365 account in a single round. All OST based email application are well-supportable from OST to Office 365 account. Through OST to Office 365 converter software you can upload OST to Office 365 account and also import OST files to Office 365 account,  pst file, EML, EMLX, MSG, HTML, MHTML, MBOX, VCF, CSV, ICS, Live, Exchange Server, Zimbra, Gmail, Yahoo, and etc.
Convert OST to PST Manually