I have been exchanging emails with people and all was okay until it started to display all threads of previous conversations like you see below. And given it's annoyance and the fact that recipient not using Gmail or free email service, they must have the inconvenience to scroll through all of this to either see/download attachments or navigate between messages because this results in excessive scrolling:
I know that Gmail is supposed to truncate duplicate messages but it seems it does no longer do so in my conversations after exchanging over 50 emails. I haven't added anything unique to previous conversations to make Gmail think there's something new to display.
How do you fix this quotation of all previous messages?