How to Reuse OST File?

Most of the organization today uses MS Outlook for communicating with their employees.  MS Outlook has the capability to work in offline mode when it is not connected to the exchange server. Basically what MS Outlook does that it creates OST file (Offline Storage Table) when you select the option ‘Use offline folder’ or ‘Cached Exchange Mode’, These OST files are not actual file but the replica of exchange mailbox stored on hard disk of your computer. You can make any modification on OST file data even when you are not connected to exchange server, any update to these OST file get reflected to exchange mailbox when connected to the exchange server.

But sometimes you face situations like OST file turn into orphaned or unusable, lets discuss possible reasons behind this issue:

Microsoft Exchange server store email, calendar, task, address book, journal and other data in exchange mailbox, if the exchange server crashes OST file associated with the exchange mailbox becomes unusable or orphaned and some others reasons are listed below:

• If the mailbox is accidently deleted from the exchange server then the corresponding OST file no longer usable
• If you mistakenly change the MAPI (Messaging Application Programming Interface) or domain setting in Outlook  then the equivalent OST file become orphaned
• Failure of hard drive at Microsoft exchange server causes damage in database at server side, this may turns respective OST file Orphaned.
• If Private encryption key is lost from mailbox and MAPI, then problem occurs in synchronization OST file and Synchronization process fails. In such case, the OST files become orphaned.

 Feasible Solutions

You can convert orphaned OST file into usable OST file by doing re-synchronization process between Outlook OST file and Microsoft Exchange Server, by performing these steps

• First of all connect Outlook with original MAPI. 
• Then connect Original Microsoft Exchange Server with that MAPI address.

Drawback

One can reuse orphaned Outlook OST file only when Resynchronization between OST file and Exchange server is possible and this could be possible only when you have original MAPI address.