If you want to convert your Thunderbird to Outlook 365 then you will go with this informative article Migrate From Thunderbird To Outlook 365. Here you will get the most efficient and effective manual methods to accomplish the process. Therefore, additionally, they will also offer a professional solution Thunderbird Backup Tool. It is a full-fledged utility that saves your Thunderbird mailbox to PST, PDF, EML, MSG, JPG, HTML, etc. You can split your large resultant PST file into small parts through the split resultant PST feature. It supports all versions of the Windows operating system. You can download the free demo version of the software to analyze the performance.