https://www.thunderbird.net/en-US/thunderbird/all/ I don't know which old versions are available.

''<p>caspermehloslawgroup [[#question-1498911|said]]</p>'' <blockquote>Hello, I want to download an old version of Thunderbird (68.9 or earlier) to conduct research. I visited the following website: https://ftp.mozilla.org/pub/mozilla.org/thunderbird/releases/ to download 68.9 and was met with a series of links and confusing pages with no clear "download" button. Please help me find the download link for this older version of Thunderbird, as it is imperative that I download it in order to complete my research. Please forward any links to my account email and [edited] at your earliest convenience. Thank you. </blockquote> Each link is basically a folder in text form. If you are using 64-bit Windows then you will want /win64/ then you pick the folder of the language you want as there are two English options. Then download the Thunderbird Setup 68.9.0.exe Also nobody here will be contacting you by a publicly posted email address.