Mailchimp is required to enforce anti-spam laws, including the U.S. CAN-SPAM Act. This means you must include an unsubscribe link in your email campaigns. A spotty unsubscribe process can impact deliverability rates, and we want to make sure your emails reach their recipients.
It's not just that an unsubscribe link is a requirement of our Terms and the CAN-SPAM Act. As a bulk delivery service, ISPs require us to manage your audiences in a specific way, so we have to be able to:
Report abuse and other information to ISP feedback loops. ISPs closely monitor how many unsubscribes occur. If an ISP sees too many, it can lead to deliverability issues for your account and other Mailchimp users accounts.