Mozilla has released today Thunderbird 6.0, this new release of the the open source cross-platform email client and news reader comes with some new features and many bugs fix.
Installation of thunderbird 6.0 in Ubuntu and LinuxMint:
Mozilla Thunderbird 6 also available on PPA, you can install / Upgradeto this latest release via the following PPA :
sudo add-apt-repository ppa:mozillateam/thunderbird-stable sudo apt-get update sudo apt-get install thunderbird
For other Linux distribution, you can download Thunderbird 6.0 from this Link