A distribution list is like an email list. The list is a group of addresses; when you send to the distribution list email address, it distributes it to everyone.
Accessing Distribution Lists
To access Distribution Lists:
In MS Exchange, click the Distribution Lists link.
The Summary screen displays, which allows you to create, edit and delete distribution lists. If it is the first time you are using Hosted Exchange, or if you have deleted all of your distribution lists, you will see the "empty" Summary screen.