IMCEAEX address format

[mrroth]

Hi,
Environment: Windows 2003/Exchange 2003, Entourage 2004
Problem: When I try to address a message, the display shows
IMCEAEX-_O=companyname_OU=xxx_CN=RECIPIENTS_CN=emailaddress
How can I hide/disable this format?
If I actually send the message, I get a Delivery Status Notification

(companyname, xxx, emailaddress have been changed to protect the
innocent)