Mailchimp is a service for sending bulk emails. We've integrated with them so that you can send bulk emails from Planning Center People to the people in your church. Mailchimp has a free plan, and they offer discounts for registered nonprofits.
Notice
Only one Mailchimp account can be integrated with a Planning Center organization.
You can connect your Mailchimp account to Planning Center from the Integrations tab. Click Connect to Mailchimp and log in.

Important
You must have permissions of at least Manager in your Mailchimp account in order to log in.
Lists in People will sync to different tags of a single Mailchimp audience. This is best because a single email address on two different Mailchimp lists counts against your Mailchimp account limits twice, but there is no such limitation to tags of a single audience.
Choose the pre-created audience from the dropdown.

Click on Change audience in order to change what Mailchimp list Planning Center uses, or click Disconnect to remove the integration.

Once you connect to Mailchimp, you can send an email to a list of people from Planning Center people.