Convert Unlimited PST Contacts - Version 4.0 Conversion of anything is obviously a difficult task because there is lots of chances of data lose. If you are going to convert Outlook Address Book, you should be very careful cause of many reasons like MS Outlook saves all the information in a PST file or MS Outlook doesn't provide any option to convert unlimited PST contacts. You can try third party tool to convert unlimited PST Contacts in one go and you can easily convert Outlook Address Book to some other email application. Just try SysTools vCard Export to solve this problem. Software converts Outlook Contacts without any limitation or converts unlimited PST Contacts to some other software. MS Outlook also provides Export option for contacts conversion than why we need to use any software for contacts conversion. MS Outlook “Export” option is useful in the case of limited Outlook contacts conversion because it converts contacts one by one. If you need to convert only 10 or 15 Outlook contacts, it may be a good option. However, if you use conversion software, you can convert unlimited PST contacts at a time.