Imagine the scenario where you and I converse on a subject via email. Each time we reply to the other's email, we include all the message along with our response. If we strictly alternate our replies, then clearly I can delete all but the last message and retain the entire conversation.
Now add several more people to this scenario and remove the strict alternation of replies such that the latest message no longer contains the entire conversation.
Is there a tool that can delete messages in the thread such that the entire thread can be reviewed with a minimum number of messages?
Or, take it to the next level and merge all responses in such a way as to preserve the entire conversation in a single message.