If you are looking to transfer Thunderbird to Outlook 365 then you will go with this informative article
Migrate From Thunderbird To Outlook 365. Here you will get the most reliable manual method to accomplish the process. However, the manual method is a high chance of risk. Therefore, they will also introduce an advance solution
Mozilla Thunderbird Backup Tool. The software is a full-fledged utility that save and migrate your Thunderbird to different file folders and email clients. It is a simple user-friendly and does not require to technical knowledge to use. They are flawless compatible with all versions of the Windows operating system. You can try the ful- featured trial version of the software to analyze the performance.