If you are looking for effortless solution to import Thunderbird emails to Outlook PST file format then you can utilize
ZOOK Thunderbird to Outlook converter tool. It is the best utility to transfer Thunderbird mailbox data to Outlook. It allows users to batch export Thunderbird files to Outlook 2021, 2019, 2016, 2013 and all below versions. This utility protects entire data integrity and original folder hierarchy of Thunderbird files into resultant Outlook PST file. It is capable to repair corrupted or orphaned Thunderbird files and export them into Outlook.