From Header: Use your List Address.

In the typical Discussion Group message, the email address in the From Line is the person who sent the message. 

Your account has an option to show the List Address along with the sender's email address. The computers only see the List Address in the From Line. Your Subscribers will see both addresses and recognize who the message is from.

Why to Use This Setting

Another benefit of using your List Address in the From Line is improved inbox delivery.

For more details and instructions how to use this setting, please see this post:

List Address in From Line can improve delivery: For all Subscribers