On the Start menu, point to
Programs, point to Administrative Tools, and then
click Active Directory Users and Computers.
In the console tree, expand the Windows 2000 domain.
Double-click Users, or double-click the node that contains
the recipient information you want to modify.
In the details pane, right-click the user you want to modify,
and then click Exchange Tasks.
In Exchange Task Wizard, click Next, select
Create Mailbox, and then click Next.
Verify that the information, in Alias, and in the
Server and Mailbox Store drop-down lists, is correct,
and then click Next