If you use G Suite (formerly Google Apps), you can create email distribution lists that will send to multiple email addresses inside and outside the organization. You can even allow people outside the organization to send to the distribution list.
Let's say your small business wants to publish an email address that anyone in the world can email, such as [email protected], and you want emails sent to that address to go to a group of people. Here's how to create a group in Google Apps to do that.
Optionally set Allow members outside your organization.
Click Add members to [group name]. Click the plus button to add individuals. Or, to create a group that includes all users in your domain, click Advanced, and check the box for Add all current and future users … You can even add email addresses from outside your domain. Learn more about editing a group.