"save history when conversations are closed"
That is a preferences option in Message app on El Capitan. I do NOT have this box checked, yet every time I log into Messages EVERY conversation from at least the last week, if not longer, populates the app. How do I get this to stop happening and start fresh each new login session? And is it possible to have the Messages app synced with the iOS Messages for when I delete a conversation - having it deleted on both?