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.
To set the footer contact info. log into your MailChimp account at https://mailchimp.com and click on the Lists tab at the top of the screen and then click on the name of the list you wish to manage.
On the following screen, under the Settings tab, click on Required email footer content. This is where you can change the designated contact, mailing address, etc. After clicking Save, all future emails will reflect the new info.