You can remove an e-mail address from a mailbox-enabled user or
a mail-enabled recipient. This is helpful when the recipient no
longer needs an address of a certain address type.
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, double-click the recipient you are
modifying.
In the E-mail Addresses tab, select the address you want
to remove, and then click Remove.