If you want to Convert MBOX file to PST file then I want to tell you there are two way where you can Convert your MBOX file to PST file (i) Manual method (ii) by using any third party tool. Manual method is very hard to use. So I want to Suggest you try this

If you want to Export MBOX in Thunderbird? then I want to tell solution where you can get all the details of importing files to Thunderbird from various sources. Here are some of these sources: If you have exported various file formats into MBOX which should be imported to Thunderbird Application. You have old MBOX