you need the best and most accurate software, so I recommend you use the MacProToolsOST to PST Converter tool. It helps to convert OST mailboxes to multiple file formats, like PDF, EML, MSG, MBOX, etc., with all email attachments. It also imports the OST file to many email clients, such as Gmail, Yahoo Mail, Thunderbird, Office 365, Hotmail, and so on, without having trouble. The software is more reliable and secure.