If you are looking for MBOX file to PDF format then EmailsGuru MBOX to PDF Converter is desirable tool. It is designed to save or convert MBOX file to PDF file, preserving all email data, attachments and original data integrity. It is capable to convert MBOX files to PDF of more than 30 email clients like Mozilla Thunderbird, Yahoo Mail, Opera Mail, Apple Mail Netscape, etc. It's simple interface offers direct option to convert single or multiple MBOX files into PDF format in a single process. Users can also use a free demo version without buying.
A reasonable question, but the only post is a vendor plug for one converter. The honest approach is to decide first whether you need individual PDFs or one merged file, then test any tool on a small sample, since attachment handling is where most converters fail. Back up the original MBOX before converting. More at https://leons-bets.gr.