[ Thanks to Dart for
this link. ]
“Thunderbird Conversations add-on is developed by Jonathan
Protzenko from Mozilla Labs Team.
“hunderbird Conversations will only work with latest Thunderbird
3.3 Miramar which itself is in Alpha stage. Since both add-on and
client is in alpha stage, use them cautiously. To download latest
version of Thunderbird 3 Miramar, run the following commands.”