OST or .ost files are related to your MS Outlook application. OST stands for Offline Storage Table file and helps in accessing your mailboxes, even if you are not connected to the Exchange Server. Also in cases of any problem with the Exchange Server database, these OST files are extremely helpful, as you can convert OST to PST and again access your mail account through your Outlook.
MS Outlook is an email client and stores all your mail related transactions, including the emails, contacts, calendar entries, notes, journals etc. in a PST file. Similarly, MS Exchange Server is a server side application that allows you to configure a number of email accounts and provides options to manage them easily. Moreover, the Exchange Server database stores all the mail transactions in it. And that is why it has been a great option for organizations to host their own Exchange Servers rather than relying on third-party mail servers.
Now, discussing the significance of the OST files, when you go offline, your Outlook application makes an exact copy of your mailbox on Exchange Server in your local computer as an OST file. The location of the OST file can be - C:\Documents and Settings\\Local Settings\Application Data\Microsoft\Outlook.
With OST files, you can access your mailboxes, make changes in it and the changes will take effect, when the Outlook will get connected to the Exchange Server. These OST files, not only allow accessing mailboxes in conditions of limited or unreliable networks, but helps in recovering mail items in cases of any trouble. Below are some of the instances, when your locally stored OST files can be immensely helpful in restoring your mail components:
-Mailbox got deleted or migrated from the Exchange Server
-The Exchange Server database has been corrupt
-Exchange Server has been down for long or got crashed
-Damage or modification to the Exchange profile
-The name of the mail server has been changed
In any of the above situations, you can take the help of any OST to PST converter utility and convert the OST file into equivalent PST. This PST file can be easily imported into the Outlook and you will get your mail items back. Among many such available utilities, Stellar Phoenix OST to PST Converter is a reliable OST Recovery tool that works well with all major MS Outlook versions and recovers mail items, without making any change in their original format. Moreover, the process of the OST to PST Converter software is pretty simple and is absolutely easy-to-use, even for the non-technical Outlook users.