Outlook Express freezes computer

I use Windows XP Pro which has Outlook Express (OE) 6. Today, November 28, 2002, is when I first noticed that starting OE causes my computer to run slow, almost freeze, while “receiving mail” is displayed in the lower-right corner. I’ve tried rebooting a few times and shutting down once to no avail. I tried Outlook 97 but the same thing happens. Why?

Thanks in advance.