Is one-click unsubscribe required by Gmail/Yahoo?

Short answer: yes. Gmail and Yahoo Mail made one-click unsubscribe mandatory for bulk senders of marketing and promotional email as part of their 2024 sender requirements. If you're sending more than 5,000 messages a day to Gmail addresses, this applies to you.

What that means technically is that your emails need two specific headers: List-Unsubscribe (with a valid HTTPS URL) and List-Unsubscribe-Post. Together, these let Gmail and Yahoo surface an unsubscribe button right inside their interface. When a recipient clicks it, their mail client sends a POST request to your URL and processes the removal. No forwarding to a browser, no confirming again. One click, done. If you want the full technical picture, the List-Unsubscribe header mechanics are worth understanding before you build this out.

The requirement is scoped to marketing and promotional messages. Transactional emails like order confirmations, password resets, and account alerts don't fall under the same rule. That said, giving people a way to opt out of transactional email is still a reasonable thing to do (within reason).

Most modern ESPs handle this automatically. If you're on Mailchimp, Klaviyo, or Brevo, they likely added the right headers for you. If you're managing your own sending infrastructure or using a more custom setup, you'll need to confirm both headers are present and that your unsubscribe endpoint actually works. A broken or slow endpoint is treated the same as a missing one.

What happens if you ignore this? Gmail and Yahoo can reject or route your mail to spam. Beyond the technical consequences, if people can't easily unsubscribe, they hit the spam button instead. And this doesn't replace your in-email unsubscribe link either. You still need that too.