If you are searching to convert Thunderbird to Outlook 365 then you can opt for an informative article Migrate From Thunderbird To Outlook 365. Here, you will get the complete manual procedure to accomplish the process. However, the manual method is soo lengthy and time-consuming. So, additional, they will also offer an advanced solution Thunderbird Backup Tool. The software is a full-fledged utility that saves your Thunderbird mailbox to PST, PDF, EML, EMLX, CSV, HTML, etc. They safely migrate or backup Thunderbird emails to dillfernt email clinet and files or folders. You can backup Thunderbird Mail with or without attachments your selected location on the machine. To explore the performance you can download it.