We're running Exchange 2007 and Outlook 2003. I'm able to create a new user
account and send mail to the new address. However, the Outlook clients do not
see the new user listed under the Global Address List. Therefore, the "Check
Names" button doesn't work, and neither does sending to just the alias (w/o
@domain.com). Again, emailing to the full email address does work.

Is there something that needs to be set on the Exchange or Outlook side?

Thanks.