Mozilla Thunderbird and Outlook supports different file format therefore we need a professional application tool. Because manual way needs addition program and internet connection. After that there is no gurantee to convert entire mailbox.
While MailsDaddy Thunderbird to Outlook Converter tool is the best solution to transfer every single emails from Thunderbird account to Outlook, EML, MSG, HTML etc. This professional application tool preserves folder hierarchy, header and other properties during the whole migration. The application comes with the trial edition that convert up to 20 emails from each folder. Read more: https://www.mailsdaddy.com/thunderbird-to-outlook-converter/