What Is the FileHippo Safety Guarantee?
* Thunderbird is based on the new Mozilla Gecko 9 engine
* New opt-in system for users to send performance and usability data back to Mozilla to improve future versions of Thunderbird
* Additional support for Personas in the compose and address book windows
* Better keyboard handling for attachments
* Windows users can hide the menu bar (and show it with the "alt" key)
* Several user interface fixes and improvements
* Fixed several security issues