The list-unsubscribe header is a built-in “unsubscribe” option provided by major email services like Gmail and Outlook. When an email includes list-unsubscribe instructions in its header, recipients can easily opt out of your mailing list without having to locate the unsubscribe link within the email itself.
Why list-unsubscribe header is good for email deliverability
This feature follows deliverability best practices! It provides subscribers with a simple and secure way to unsubscribe, helping to minimize complaints while protecting your sender reputation. By offering this as an alternative, recipients are less likely to mark your emails as spam or file abuse complaints.
Can this be disabled?
No, this cannot be disabled, as this is an RFC/industry standard.
Why I’m not getting the unsubscribe option in the email header
The unsubscribe option is only shown for senders with a high reputation. This only works for some senders right now. We’re actively encouraging senders to support auto-unsubscribe — we think 100% should. We won’t provide the unsubscribe option on messages from spammers: we can’t trust that they’ll actually unsubscribe you, and they might even send you more spam.
So you’ll only see the unsubscribe option for senders that we’re pretty sure are not spammers and will actually honor your unsubscribe request. We’re being pretty conservative about which senders to trust in the beginning; over time, we hope to offer the ability to unsubscribe from more emails.