We have mentioned the best software that helps to export PST to MBOX file, the software is KDETools PST to MBOX Converter Software. You can also convert the corrupt or normal PST file and save data into various file format such as- PST, MSG, EML, PDF, HTML. There are no file size limitations as the software is capable to import any file size without error. 

CLICK HERE:  https://www.kdetools.com/pst/mbox/