[2005] Resolve email address with exchange using networkID

Howdy, another exchange question.
When setting up outlook to an exchange server it allows you to enter your network ID (for example CJMRDC225), which it then resolves to your email address. Is there a way to ask the exchange server what the email address for a network login is? I'm looking for a way to automatically email employees, but the information I have access to either will have to be manually updated, or I'll need to be able to pull the email address from exchange using the NT Logon of the specific user.

Any ideas?