Download the most effective tool and that name is vMail OST to PSTConverter Software to easily recover and convert OST files to PST, EML, MSG, MBOX, EMLX, vCal, vCard file formats. Conversion of multiple mailboxes from OST to PST is also possible. This converter assures that there will be no data loss during the process of the conversion. You can also see the preview of the converter so that you can convert the data with no errors. You can also try the free demo version of the converter and convert 30 emails for free.