Distribution Lists - Add Members

This screen allows you to add members.

First, you select the mailbox of the person you want to add to the distribution list:

(Note: you can select multiple mailboxes at a time, and if you select the checkbox next to "Full Name" at the top of the list, it selects all mailboxes for you.)

Then click Add to Group:

The mailbox you added now appears in the "Member of" area: