Outlook Express shares the settings for the two most restrictive security zones used in Microsoft Internet Explorer, the Internet zone and the Restricted Sites zone. Therefore, for example, if you have set your Internet zone in Internet Explorer to reject Web pages with active content (such as ActiveX controls or Java applets), Outlook Express also rejects HTML messages with the same kind of active content.
SEE ALSO
For information about security zones, see "Using Security Zones and Security Levels."
NOTE
These security settings affect only the receipt of Rich Text (HTML) messages. Because of their limited capability, Plain Text messages can't contain any potentially harmful objects, such as Java applets.
To change your security zone settings in Outlook Express, choose Options from the Tools menu, and click the Security tab. Select either Internet Zone or Restricted Sites Zone. If you want to review or change the settings for the selected zone, select the Security tab of Internet Explorer's Options menu. Outlook Express will then use these same settings for the zone you've chosen in Outlook Express.