~/.thunderbird/folder. The profile folder is untouched when Thunderbird is reinstalled or updated. This keeps messages intact.
Thunderbird has a profile manager to manage different profiles. In this section we will create a new profile for each account, so that we can take manage each profile configuration differently. Thnuderbird profile manger has to be started by closing all opened thunderbird instances. then running following command.
$thunderbird -ProfileManagerNow click on Create Profile.
The current profile can be seen via "Help" menu, click "Troubleshooting Information", then on "Application Basics" section, go to line "Profile Directory: and then click on "Open Directory".