Thunder bird MBOX files can be imported to Outlook PST because of many reasons. One of them are Outlook email client are also used in offline mode. Best Manual methods are available here and user can know about these methods from here, visit:
Try a third-party platform to convert all MBOX data to PST and other formats for the best and easiest solution. MBOX to PST Converter tool, in my opinion, is the best choice for MBOX to PST conversion. It offers a variety of options and converts multiple MBOX files to Outlook PST, EML, and MSG formats quickly and painlessly. It supports all versions of Outlook, and Windows OS. Download its demo to test the tool and converts the first few data items per folder. Refer:- https://www.sysessential.com/mbox-to-pst-converter/
Both Manual and Automated method is available to convert Thunderbird MBOX to PST but you may lose your existing data while converting your Thunderbird files to PST format through manual method, so choose best Thunderbird Converter program, fully automated solution to convert Thunderbird to Outlook PST folder all along with complete data, attachment files, etc, Batch file conversion is also possible with no data loss at all.
You can opt for the professional MigrateEmails Thunderbird Backup Tool to easily convert Thunderbird emails to Outlook PST format. This tool enables a quick and secure migration of Thunderbird emails with utmost accuracy. Users can convert multiple Thunderbird emails into PST format in just a few clicks. This tool also allows to backup of Thunderbird emails to external hard drives in PST, PDF, MSG, EML, MBOX, etc. Further, users can migrate Thunderbird emails to Gmail, Office 365, G Suite, etc.