Starting with Thunderbird version 52, Thunderbird requires Mac OS X 10.9 (Mavericks) or higher. If you are on an earlier version of Mac OS X, there are options for you to continue using a secure version of Thunderbird.
Mozilla Firefox For Mac Os X 10.6.8
Note: If you have Mac OS X 10.7 (Lion) or 10.6 (Snow Leopard), you will need to download OS X El Capitan before you can upgrade to the latest Mac OS. While insecure versions of Firefox will continue to work on OS X 10.8 and earlier, using an up-to-date version of Firefox on a supported version of Mac OS will provide you with the best and safest. On August 2, 2016, Firefox 48.0 was released. It is scheduled to be replaced by Firefox 49.0 on September 13, 2016. At that point, Mac users using OS X 10.6 Snow Leopard, 10.7 Lion, and 10.8 Mountain Lion will be left behind by the current versions of Firefox. It will be a sad day, as Firefox is the last major browser to support Mac OS X 10.6 through 10.8. The Firefox version 48 release in August 2016 will be the last Firefox version to receive new feature or security updates on OS X systems that are no longer supported by Apple: OS X 10.6, 10.7 and 10.8. Mac users interested in Firefox version for os x 10.8.5. Generally download: Firefox 80.0 Free Firefox is one of the most popular web browsers on the market, providing numerous helpful features and quick speed to millions of users worldwide.
Visit this Apple Support page to find your Mac OS version.
Download Mozilla Firefox For Mac Os X 10.6.8
To ensure the safest email experience, we recommend upgrading to a Mac OS version that Apple supports. Visit this Apple Support Page to learn more about upgrading.
While Thunderbird will still continue to work on unsupported versions, using Thunderbird on a supported version will provide you with the best and safest user experience.
Mozilla Firefox For Mac 10.6.8 Free Download
Thunderbird 45 will continue to work with Mac OS X 10.6, 10.7 and 10.8 but will not receive any further updates or security fixes. Thunderbird 45 can be downloaded from here. First pick the folder for your locale and then download the package.