To keep the names and e-mail addresses of people included on a personal distribution list private, or hidden, use the Bcc field.
Note: It's not possible to display the distribution list name in the To box, without allowing it to be expanded to show the entire list of names and e-mail addresses. This procedure suggests using the sender's name in the To box.
In an open message, add your e-mail address in the To box.
In the Bcc box, add the distribution list.
Type your message and click Send.
I dont see the Bcc box.
In an open message, on the Message Options tab, in the Fields group, click Show Bcc.