OWA 2010 gives a new view for emails by default, which is termed “Conversation View”. It will be the same in Outlook 2010 as well.
The view that we are used to in all versions of outlook and OWA till date is “arrange by date”. A snapshot is shown below.
The conversation view sorts all these lengthy emails by conversation. So, all the emails shown above is shown as a single entry.
You can expand the emails and it will shows a snapshot of all the replies that has come for that conversation.