Which version of Internet Explorer is Outlook 2003 using to render?
Outlook 2003 uses which ever version of Internet Explorer the user has installed, in Litmus' case, it's version 7.
How important is it that my email renders correctly in Outlook?
Based on our aggregated Email Analytics data, Outlook 2000, 2002 and 2003 combined represent 31.54% of global email client market share. That figure is reducing each month, though, presumably due to users upgrading to Outlook 2007 or 2010.