New versions of open source email client Thunderbird are available for download — with either a handful of new features or a shedload, depending on which you pick. Thunderbird 140 is the latest monthly update, while Thunderbird 140 ESR is the newest ‘extended support maintenance’ release (that , Stable Thunderbird release that gets frequent new features, improvements, bug fixes and security patches., Thunderbird Release Don't wait a year for improvements, updates, and fixes. Enjoy the right balance of speed and stability for most users by switching to Thunderbird Release., Good news for Mozilla Thunderbird users! Mozilla team has released Thunderbird 140.0 version to the new Release channel. The versions available on Release channel are provided for testing purposes only. If you want a stable version of Thunderbird to use on primary machine, you should use Thunderbird ESR version., Version 140 of the Thunderbird mail client has been released. Notable features include "dark message mode" to adapt message content to dark mode, the ability to easily transfer desktop settings to the mobile Thunderbird client, experimental support for Microsoft Exchange, as well as global controls for message threading and sort order., .