Listing of all emails fron a sender and not just the ones sent between a particular exchange/conversation

I have noticed that emails recieved in hotmail may have a number next to the senders address - and it appears that all the messages sent between yours and the senders email are now displayed below the new message. Is it possible to return to the situation where the only messages that are included in an email are the ones directly related to the particular current exchange of email without listing every email ever sent between a sender and reciever?