Threading of Confluence emails needs to be better

The new "auto watch" feature on Confluence is cool. I previously never used Confluence notification emails before.

However they dont thread in Thunderbird.

Some people have suggested that its related to the message id not being used correctly. Whatever the cause it would be great of the notifications threaded.

Note they do thread in Gmail but then I am not using Gmail. I hate Gmail threading with its collapsedness and not seeing stuff....