WARNING : a backup of your profile (.thunderbird directory) seems mandatory.

Start by reading :

As always :

yum --enablerepo=remi update thunderbird

The enigmail and lightning extensions are also available.

This new version introduce some new features, including the New Search (this can be disabled).

Build for Fedora 8 to 10 are available (those for Fedora 11 and 12 are in updates-testing).