Search before Outlook 12
Search in Outlook 2003 had many issues that prevented users from taking full advantage of it as a primary means of interacting with their mail data.
The Find UI was not visible by default, and most users did not know how to turn it on. Those that turned it off were unable to turn it back on. It also had significant UI complexity, i.e. too many knobs and levers that blended in with each other and obfuscated their purpose. The Advanced Find UI was very complicated and difficult to use for most users.
Most importantly, search in Outlook 2003 was slow. The lack of speed was crippling to most users and compounded the problems with the UI. It was very difficult to search across different store types, and that worked against Outlook’s goal of being able to access so many different types of data stores.
The New Search Lexicon
Search was never considered a primary means of finding information in Outlook. We have taught our users to use folders and flagging systems to help keep mail organized and make it easier to find when needed.
Now that Search returns sub-second results, we can confidently state that Search is the predominant way we want our users to find their information. Users can now move away from folder-based filing systems if they'd like and use Search to always find the items they need, no matter what folder or store they are in. If you prefer to maintain a folder-based filing system (like I do), then our scoping model means you just click a folder and instantly search just its contents, with the ability to up-scope to All Mail Items with just one click.
The new Outlook 12 Search replaces the UI from Outlook 2003’s Find system with the new Search Pane. Along with the Query Builder and view filtering, this new UI represents an entirely new way for users to interact with their Outlook items. Scoped, item-level filtering means that using Search to pare down your view to see less items and find the one you want is a vast improvement over search in 2003.