Mozilla has released Thunderbird 2 in 30 different languages. Thunderbird 2 is a free open source e-mail client for Windows, Mac, and Linux.
Security has been improved and many new features have been added. Possibly the biggest new feature is message tagging, which makes it possible to label and categorize e-mail for easier searching and organization. Users can create their own tags in addition to the default tags.
There are security features in Thunderbird 2 such as S/MIME, message encryption, digital signing, and support for certificates and security hardware. Thunderbird 2 does not allow script execution by default.
Here is a Mozilla link that will give you much more information and the opportunity to download Thunderbird 2 if you are interested
Thunderbird - Reclaim your inbox