Yes, but you have to deal with this. https://support.mozilla.org/en-US/kb/dedicated-profile-thunderbird-installation You also need to be aware that each version contains many bug fixes and security fixes. https://www.mozilla.org/en-US/security/known-vulnerabilities/thunderbird/ Going backwards is largely asking for trouble, hence many like myself remain on the ESR release which updates once a year, gets those security fixes and does not have as many issues with addons not being updated before the monthly release makes it obsolete. You actually get to choose to use/download the ESR version here https://www.thunderbird.net/en-US/thunderbird/all/ the big bold download button on the main page will always offer the monthly release.