Thunderbird //free\\ Download Archive Page

Major updates (like the shift to "Supernova") often break older extensions. Users may download an archived version to continue using mission-critical legacy add-ons.

Using archived software carries risks. Older versions lack the latest security patches, making your system more vulnerable to exploits. If you must use an older version, consider it a temporary measure or use it on a machine with restricted internet access. How to download older versions of Thunderbird thunderbird download archive

Modern Thunderbird versions may refuse to open a profile used by a newer version. On Windows, you can bypass this by running the application through the "Run" dialog (Win+R) with the command: thunderbird.exe -P --allow-downgrade . Major updates (like the shift to "Supernova") often