Most of Outlook users have face problem with OST file after disaster of Exchange Server because an OST file may be corrupted. It is only one resource that get back Outlook emails on offline Exchange Server. The email clients need solution that repair an offline OST file and export entire data from offline OST file to Outlook PST file format. The manual process offered by  Microsoft is isolated solution or try third party OST File Converter tool that restore offline OST file from client machine and process them to export into Outlook Personal Folder Pst files.

There are two valuable options for Converting Offline OST file to Outlook Personal Folder PST file which is following:-

Manual Process: It is most popular method offered by Microsoft to easily export data from OST file to MS Outlook PST file format. It is totally free solution but it only supports that OST file which is created by MS Exchange Server 2003 and lower version.

1. Open Microsoft Outlook Application
   
2. Mouse Click On File Menu
   
3. Choose Option the “Import and Export” wizard or press ‘t’.
4. From the list, click the “Export to a file” option and then mouse click on Next button.
   
5. Select Outlook Data File (.pst) and then mouse click on Next button.
6. Selected items to be exported or Click on parent root and check the Include sub-folders option.
   
7. Browse and select the target folder for saving the email items.
8. Mouse Click on the Finish button.

Note: Manual process only process OST file created by Microsoft Exchange Server 2003 and older versions, if you have an OST file which is created by Microsoft Exchange Server 2007 and upper version then Manual process fails in recovery of OST files. In such condition you can try third party Software.

Third Party Tools: There are number of third party tools available online but most of the tools consume huge time in recovery process.  I would like to suggest you one such professional and ideal solution Voimakas Exchange OST Recovery  which can be easily recover emails from corrupted or inaccessible OST file and export all data from offline OST file to Outlook Personal folder (PST) files within few minutes.