https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer

It looks like you copied some account information into the profile folder, as the profiles folder itself appears in your screenshot. Do you still have the old computer. Assuming windows, here are the steps: Here is the link for moving a profile in Windows when installed in default location: https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer here is the info in brief steps: # ensure thunderbird is NOT running on old machine # enter %appdata% in search window on task bar and press Enter key # this should open windows file explorer in Appdata\roaming folder # highlight the Thunderbird folder and copy to external media # ensure thunderbird is installed on second computer and NOT running # enter %appdata% in search window on task bar and press Enter key # you should be in Appdata\roaming folder , copy&paste the exported Thunderbird folder there. This may prompt to overwrite an existing folder of same name. allow it # start thunderbird and all should be there If the old computer is no longer available, can you post a screenshot of the exported profile so someone here can advise on how best to transfer it? That will help. Thank you