Google Mail sorts e-mail messages into “conversations” – basically, all the messages with the same subject line are stacked on top of each other. If a new message comes in, the entire stack moves to the top. You can immediately see the context for a message. Labeling and archiving happens to entire conversations.
Some people engage in lengthy exchanges with a group of correspondents with the same subject line used continuously. Those people love Google Mail’s conversation view. They can’t understand why anyone would use Outlook and display messages in chronological order.
(Personally, I find conversation view to be infuriating. My mind doesn’t work that way, my e-mail flow doesn’t happen that way, and at some deep level I just don’t get it. I’m much more in tune with all the people who find this page when they look for a way to disable Google Mail’s conversation view. It can’t be turned off, by the way.)
Outlook 2003 and 2007 both permit folders to be arranged in conversations. (Click on View / Arrange By – weird, huh? It was there all along.)
The conversation arrangement in Outlook does not gather messages from all folders, and that makes it fairly useless. Your half of the conversation is stored in Sent Items and won’t show up in the conversation threads in your Inbox.
Microsoft’s Outlook team just wrote a description of the “ultimate Inbox” – how to set up a rule that automatically moves your outgoing messages to your Inbox, where they can be included in the conversation view. Interesting trick!