The CAN-SPAM Act (https://www.ftc.gov/tips-advice/business-center/guidance/can-spam-act-compliance-guide-business) requires that all emails contain clear contact info. for the sender of the email including a physical mailing address. MailChimp complies with this by automatically adding the necessary info, as well as an unsubscribe link, to the footer of all email messages it sends on your behalf. You can control the contact info. shown the footer on a per-list basis. Note: Most clubs only use one mailing list and simply segment it based on account type, payment status, etc.

MailChimp has an article that covers this topic, including the rules for using their service here: https://mailchimp.com/help/anti-spam-requirements-for-email/

To set the footer contact info. log into your MailChimp account at https://mailchimp.com and click on the Profile icon at the top right of the screen. From the drop down menu that appears choose Account.

On the following screen, under the Settings tab, click on Contact Information.

If you scroll to the bottom of that screen you'll see a section titled Audiences in this account. Audiences are what MailChimp calls lists. For each list you have you'll see the current contact info. as well as a link to change it. Click on Edit Audience Information to change what is displayed in your email footer.