Need for change of view for e-mail clients

I really feel distracted when I have to switch back and forth between Inbox and Sent Items of Outlook/Outlook Express to search related mails in order to construct a complete conversation on certain topic between a few parties. Things went even worse when you have dozons of subfolders inside subfolders in both Inbox and Sent Items.

I want Inbox and Sent Items combined together. I want mails organized by topic intelligently (some heuristical rules and classification should be able to handle most cases). I want chronical list of incoming and outgoing mails for each topic raised. I can think of an alternative and possibly better UI view of email client -- looking like discussion forum, or newsgroup: mails are treated as posts and grouped into threads. A keyword based search engine can be implemented to facilitate searching mails.

I guess by doing some combination of "Group By" and "Sort" settings in Outlook, you can achieve that to a certain extend. So far I have not figured out a best combination.

Why mail client must have a familiar face of Inbox and Sent Items and Preview Pane? Make it look like forum, without any need to touch the underlying storage at all. If there is not such a thing out there yet, anyone want to built a frontend like this? Let me know!