To Migrate Thunderbird to Outlook then just using eSoftTools Thunderbird to Outlook Converter, it can export bulk MBOX folder in Outlook without any alterations in its bcc, cc, from, dates, attachments, and emails header, etc. It can convert any size of Thunderbird MBOX folder data, without any restriction for migration. It can allow a free demo pack in which users can convert the first 25 items of the Thunderbird mbox file.
For more info:- Migrate Thunderbird to Outlook