Offline Storage File (OST) is a local data storage file that can be created in MS Outlook to work in an Offline mode. Internet connectivity cannot be taken for granted. There can be times when the Internet connection in your organization has been lost for an hour or more. During that time, you can switch to MS Outlook’s Offline Mode and continue creating emails, adding attachments to those emails, inserting images in the emails, creating calendars invites, etc. And, when the internet connectivity will be reinstated, MS Outlook will process the work you have done offline. By taking the advantage of MS Outlook’s Offline mode, you can save your precious time that could have been wasted otherwise.
What works behind the MS Outlook’s Offline mode is the OST file. This is the file in which Outlook stores the information that can be used even in absence of Internet connectivity.
When a user profile is created in MS Outlook on Microsoft Exchange Server environment then MS Outlook creates two files on the user’s PC. One of those files is Offline Storage file (OST file) that allows the user to work in offline mode. Also, a copy (data storage file with .ost extension) of user’s mailbox is also created on Exchange Server. This is the exact replica of the OST file on the user’s PC. The second file that MS Outlook creates on user’s PC is PST file that lets you work in an online mode.
When the connection to MS Exchange Server is lost, then you can switch to Offline mode and continue using MS Outlook the same way when it is connected to the Internet. You can create emails and click the Send button. MS Outlook will move the email in the Outbox and as soon as the connection to MS Exchange server will be re-established, MS Outlook will deliver the email to the specified recipient. Like this, you can perform any action. Also, the OST file on the Exchange Server will be updated automatically so that the OST file on Exchange Server and the one on local hard disk are same.
Note: OST file is automatically created when you work in the MS Exchange Server environment. The location of OST file on your PC may vary depending upon the version of MS Outlook you have. However, the most common location for OST file is C:\Documents and Settings\Local Settings\Application Data\Microsoft\Outlook
When you work in the non-Exchange Server environment then you can create the OST file by executing the below listed steps in Outlook 2010 and above versions:
Yes, OST file is prone to damage similar to other files. There can be many reasons behind the damage of the OST file. Once the OST file is damaged, you may recover it by performing different recovery methods. For example, if you have a backup copy of the OST file, you can use that. If the OST file on the Exchange Server was damaged but the one of local hard disk is working fine, you can use that working OST file to recover the content. And, in case, there is no option left, then you can repair OST file using good OST file repair software. You can easily find the good OST file repair software on the market.
Note: Before you use any OST file repair software, we suggest you to create a copy of the corrupt OST file because we do not know, which software you are going to use. It may happen that the software may not work properly and further puts in a severe condition. If you will have the copy of the corrupt OST file then you can try different OST file repair tools without any fear of losing important data.
Also, we suggest you to use the best OST file repair and recovery software than any of the software available on the market.