what addon?

Thunderbird Conversations

So you are trying to make thunderbirds interface look like Google? That is not threading. Threading is something Thunderbird does natively and with minimal visual clarity in the card view. In the list view it uses basically the same interface elements but they are more obvious in a list.

So can you please clarify what outcome you are actually seeking.

My frame of reference is outlook but it does look like gmail does a similar thing. I would like to see all messages in a conversation grouped together. When I select a single message all messages in that conversation should be together. I have attached a couple of screen shots showing what i am seeing and what it looks like in outlook. Even when in table view i seem to have inconsistent results in the same folder.

Maybe try “Conversations” after you click on a message instead of the more general view with threading?