I want to move Thunderbird emails from old computer to new computer

I moved Thunderbird from an old XP machine to a new Win10 machine. The address books I had did not move with the profile, but I was able to export the address books to a thumbdrive and import them to the win10 machine. But my old emails did not all move over to the new machine. All of 2018 and 2019 dated emails did not move. How can I copy, export/import, just these emails dated 01-01-2018 thru 03-15-2019 to the new machine. The new machine is working, I just do not have the dates listed email messages and want to move just them if possible.