To convert MBOX files to EML format in bulk, you can use the
eSoftTools MBOX Converter—a tool trusted by many users who have achieved excellent results. It supports both selective single-file and multi-file MBOX conversions, and allows you to convert an unlimited number of emails from MBOX files into Outlook and various other formats. A free demo version is also available, which anyone can use at no cost.
Read More:- Convert MBOX to EML files in Bulk