Google Groups setup for administrators - Manual (Page 9)

Set your auto-reply for the group
1. With your group selected, click Manage
in the upper right.
2. In the list on the left, click Email options.
3. Choose the settings listed below.
Email prefix
Text added to the subject line of incoming messages so you can quickly identify
them. You might set to something like [sales-request].
Email footer
Deselect all options. These options are typically used for internal mailing lists
or groups with external members, such as a newsletter.
Auto replies
Enable auto-reply message for non-members outside the organization.
Add a message that all senders outside of your domain will receive.
Tip: include your company info as any custom email footers aren’t applied.
Learn more: Auto replies for groups
5. Train your team 1. Turn on Groups 4. Collaborative inboxes 2. Set up auto-reply 3. Add external users