MailsDaddy OST to Office 365 Migration Tool helps provide users the facility of direct conversion of data from OST to Exchange Online. A well-programmed OST to Office 365 Converter to move the On-Premise OST emails, attachments, contacts, appointments, tasks, etc. It upload OST file to Office 365 account without changing any content of the OST data. Works amazing without any restrictions and perform the give the best outcome. It is very much accurate and sustains the entire hierarchy of the Outlook OST data file.