Outlook users are able to work in offline mode with the help of OST files when a connection between Exchange server and Outlook client is not established. This is because OST files act as replicas of the Exchange Server User Account. Therefore, when the server is down, users are able to send and receive their emails through the OST files. Furthermore, they are able to compose emails and make updates in other mailbox items through the OST files. OST to PST conversion is needed when these OST files become the only source of updated user mailboxes and the server hits permanent downtime. In such times, OST files are termed as orphaned as without synchronization with MS Exchange Server their data becomes practically inaccessible. Therefore in order to access user mailbox data from orphaned OST files, OST to PST software are required. By converting OST to PST, MS Outlook email client manager can be used to read the last updated mailbox information from a local system. OST to PST software are also useful for accessing data from corrupt or damaged OST files, which ScanOST.exe utility otherwise fails to do. OST to PST software like Kernel for OST to PST Conversion effectively converts all the emails, address book entries, contact details, calendar entries, personal folders, appointment schedules and other items from OST to PST format. All types of email attachments are also supported by the OST to PST conversion tool. Also, emails in Plain Text, HTML or RTF formats are easily converted by this tool. While converting, this tool makes no alterations in the metadata, properties or internal structure of the OST file contents. Hence, OST to PST software are apt tools during Exchange server database crash or server downtime.