Here’s how it works.
Your staff will appreciate using the intuitive yet powerful MailChimp interface for building trackable email and social marketing campaigns, newsletters etc.
Meanwhile, your subscriber lists are synchronized between SharePoint and MailChimp.
Records are added to your MailChimp List from your SharePoint List.
Records are never deleted from you MailChimp List, and if someone unsubscribes from your MailChimp List, they are not re-added.
Everything is automatic, everything is logged.