Why list-unsubscribe matters

List-unsubscribe is an optional email header supported by popular inbox providers like iOS Mail, Gmail, and Outlook.com. Supported inbox providers look for this header in emails and display a native unsubscribe option to users, allowing for a simple and consistent unsubscribe action.

While it can feel counterintuitive to make it easy for subscribers to stop receiving your emails, unsubscribes are actually a good thing when they serve as an alternative to a spam complaint. Our research has shown that 50% of consumers have marked an email as spam because they couldn’t easily figure out how to unsubscribe.

How does Litmus help?

Note: a List-Unsubscribe header is different from having an unsubscribe link in your email body. Some ESPs will not include a List-Unsubscribe header in test or preview sends, in which case your results will show it's not included. If you'd like to confirm your final send will have the List-Unsubscribe header, you can do a real send (not a test or preview send) to your Litmus test address.

Litmus validates the List-Unsubscribe header record in your email, and checks it meets the right specifications. We will tell you whether a List-Unsubscribe header is set up for your email, show if you’re set up to support both the mailto and the URL version of List-Unsubscribe, and flag any issues it spots in your List-Unsubscribe header.

Keep these tips in mind when creating opt-out processes for your email campaigns:

Implement the List-Unsubscribe header in all of your marketing emails. If you're unsure how, check with your Email Service Provider, or review The Internet Society List-Unsubscribe specification.
Include a prominent unsubscribe link in every promotional email. This is a great best practice, but it's also required for any email sender to comply with international spam regulations.
Use an unsubscribe process that requires no more than one step. Aim for a single click from the email, and one additional click in the unsubscribe page or your preference center.
Ensure that unsubscribe pages and preference centers are accessible without requiring a login.
Learn more in our Email Marketers Guide to Using List-Unsubscribe