Start by reading :

As always:

yum --enablerepo=remi update thunderbird\*

enigmail (version 1.6) extension is also available.

lightning is no more available.

For Enterprise Linux 6, the build use python27 (Red Hat Software Collections 1) and devtoolset-2 for gcc 4.8.1 (Red Hat Developer Toolset 2) . (only for build, unneeded at run time). This fixes the issue explaining why Thunderbird 24.0 haven't be available.

RPM of version 24.1.0 are availalble for Fedora 14 (x86_64), 16, 17, and for Enterprise Linux 6 (and in official repository for fedora ≥ 18)