The service desk is responsible for creating user accounts and the process is completed using scripts. We are currently rewriting the script to include support for exchange 2007 mailbox creation. Until that is complete I need to manually create the mailboxes for the service desk after they create the AD account. When I go to create the new mailbox for an existing user in the 2007 console the new user does not show up. One thing I noticed is that the user creation script populates the email address field in the AD account properties. I'm wondering if this is the problem, does anyone know how the create new mailbox wizard determines which users are available to create a mailbox?