Most of the user prefer MS Outlook for sending and receiving emails. There are many other email client applications but the trusted one and featured one is MS Outlook. This Email application only supports two file format that are OST and PST. OST file is an offline storage file and PST file is an online file.
But the problem arises when the user wants to convert an OST file to PST. It sounds good that it can be converted easily but in reality it is very difficult to convert an OST file to PST via manual methods. There are chances of OST corruption as well if the user tries to convert it using manual techniques.
I would suggest to use a third party OST to PST converter software which may help you to convert OST file to online PST. You might find hundreds of software on the web but choosing an authentic and general one is quite difficult.
I have heard about OST to PST File Converter tool by Aryson which is quite common these days. Many users have good reviews about the product. In no time it converts an OST file to PST without causing any data loss. You can avail the tool from the official website of Aryson Technologies.
Adviser for Technical issues 