Goodbye sluggish Outlook
Outlook performance has been an issue since I remember. Personally, I think that Microsoft Outlook is a great application, is probably the most used application in every Organization and the first one people run whenever they turn their PC on.
Nevertheless, I do agree that performance could be better. For long time I suffered the pain of waiting 5 minutes (or more) until the Outlook window is ready to be used. The main reason for this behavior is normally a huge PST or OST file (anything bigger than a few hundred megs).
Microsoft has just released a major update that, among other things, modifies PST and OST structure, thus reducing I/O disk usage and UI response time.
Microsoft released 2 fixes (961752 and 967688), that are available through the KB article Outlook 2007 improvements in the February 2009 cumulative update.