I love Mail 5's new Conversation View. But, I don't like that it only shows messages sent to me, and doesn't show the messages I send.
Is there a way to show both messages I receive and messages I send in Conversation View?
Go to Mail-> Preferences-> Viewing and check
Include related messages (under View conversations: at the bottom).
This will show "related messages", which (as far as I can tell) means messages that you send in the same conversation.