Even if you setup a perfect double opt-in, permission-based list, follow all the anti-spam laws and email marketing best practices, and keep your database totally clean, you’ll get spam complaints. Sometimes it’s a mistake, sometimes it’s a prank, sometimes it’s a spambot, and sometimes the recipient just isn’t very bright. Spam complaints are inevitable. Luckily, there are ways you can minimize them.
Truste has published this guide that explains how spam complaints happen, what the repurcussions are to businesses, and simple things you can do to your opt-in process to keep complaints to a minimum.
By the way, MailChimp is on feedback loops with major ISPs so that we can automatically unsubscribe any members on your list who report your email as spam (Learn more about feedback loops at Clickz).