if you want to export contacts from OST to vCard, then check out GainTools OST To VCF Converter . With just a few clicks of the mouse, the software lets you quickly finish this task. It's made so that users who have never used it before can easily get contacts from an OST file without any technical help. You can pick contact files from the OST mailbox with this tool. That way, no data is lost during the process, and it is really safe. Because this app has a simple graphical user interface, even people who aren't tech-savvy can easily use its features. This is the best OST to VCF format.