There are various factors responsible for PST to MBOX Conversion. Some of them are the transformation of the Operating system, risk of PST file corruption, change of Jobs, etc. If you are looking for methods to convert Outlook PST file to MBOX, Read the post further. It contains two manual methods with easy steps to convert PST to MBOX. Additionally, It also includes a reliable tool named PST to MBOX Converter to open MBOX in Outlook.