When you open an Email in Outlook Express, the images may appear as red X's. Try the following links.

Web Page Displays an Image As a Red X or Not at All [283807]
http://support.microsoft.com/?kbid=283807

Image May Not Appear in Message Received with Outlook Express: [246186]
http://support.microsoft.com/?kbid=246186

Image May Not Appear in Message Sent with Outlook Express: [171908]
http://support.microsoft.com/?kbid=171908

OLEXP: Images in E-Mail Messages Are Missing After You Apply Stationery: [256974]
http://support.microsoft.com/?kbid=256974

Some types of images don't display [Tom Koch MS-MVP]
http://insideoe.tomsterdam.com/problems/bugs.htm#nopreview