What are.ost Files: .ost files are Offline Storage Files in Outlook. These .ost files provide ease to users to work offline. Afterwards when you get online, you find those changes, on the whole to work offline is fruitful with low connectivity or limited environments.
In large organizations, when Microsoft Outlook is in connection with Microsoft Exchange Server, you can work even when you are Exchange mailbox offline and that time, Outlook will create exact copy or replica of your mailbox which is called offline folders. Store this offline file in local file which has .ost extension.
In your organization, you have Exchange Server where all the employees are connected to it with LAN, and here OST files are created. Suppose, your administrator has switched off Exchange Server, then also you can work and the time when your administrator switch on Exchange Server, your administrator will receive synchronized OST data. Suppose one day, when you reach your organization and to your aghast, your administrator tells that Exchange Server is crashed and OST files unable to synchronize. OST cannot be used, which can be pathetic for you.
To get back OST data, employ OST to Outlook Import process, which will let you use the same damaged OST data in PST and you can use that data. For this conversion, take help from specialized app like OST Recovery software. OST to Outlook import process, with the help of this software, make damaged OST files again usable but with the only difference that the data in.pst format. With no work hamper, you will be able to access whole OST data in PST, MSG or EML, whichever, you want in.