You can try this professional tool Regain PST to Office 365 Migration Software that has capability to Migrate PST file to Office 365 Account without any issue. There is No file size limitation. You can easily select your desired PST file and Migrate them into Office 365 Account or Live Exchange Server. It can directly import the PST files without any type of damage to the original structure and properties of the file. You can easily run this application in any versions of Windows OS.