Here are the steps for converting PST to MBOX file format:
Yes, this pst converter for MAC can easily export multiple PST files at a time. For this you just need to Add Folder containing PST files.
No, the PST converter doesn’t impose any file size limitation for exporting PST emails to EML, EMLX, MSG or MBOX formats.
Yes, Software enables you to export emails of specific date range. You just need to provide date range using software date filter option.
Yes, software is well capable to support MAC OS X (10.13, 10.12, 10.11, 10.10).