http://enigmail.mozdev.org/news/index.php.html
"06/28/2011 Enigmail v1.2 has been released. This release supports Thunderbird 5.0 and SeaMonkey 2.1."
//edit:
Maybe we shouldn't package it anymore. You can simply download it as a plugin for thunderbird.
http://enigmail.mozdev.org/download/index.php.html

