This page from AuthSMTP explains how List-Unsubscribe and List-Unsubscribe-Post headers help recipients opt out of mailing lists.
To unsubscribe from a specific mailing, use the unsubscribe option in that email or contact the sender directly. The examples below are demonstrations and do not submit unsubscribe requests.
List-Unsubscribe.net
Improve deliverability and reduce spam complaints by adding machine-readable unsubscribe instructions to your emails.
What are List-Unsubscribe headers?
List-Unsubscribe is an email header defined in RFC 2369 and extended by RFC 8058. It lets inbox providers (like Gmail and Outlook) show a native Unsubscribe action next to your email. Rather than relying on a link in the body, the header advertises one or more unsubscribe methods that clients can call automatically.
- A mailto: address requests removal by email. An HTTPS URL points to an unsubscribe endpoint.
- For one-click unsubscribe, include an HTTPS URL and List-Unsubscribe-Post: List-Unsubscribe=One-Click. The mailbox provider sends an HTTP POST to request removal without another confirmation step.
- Gmail requires one-click unsubscribe for marketing and subscription messages from bulk senders sending 5,000 or more messages a day to personal Gmail accounts. A mailto link or a web preferences page alone does not meet that requirement.
Interactive Header Example
Toggle the options to compare example headers. The addresses are placeholders; production links must identify the correct recipient and mailing. Adding headers alone does not create a working unsubscribe service.
- From Domain
example.com- Mailto Address
unsubscribe@example.com- HTTPS Unsubscribe URL
https://example.com/unsub/abc123
Generated Headers
List-Unsubscribe: <mailto:unsubscribe@example.com>, <https://example.com/unsub/abc123> List-Unsubscribe-Post: List-Unsubscribe=One-Click
Preview
- From
- updates@example.com
- To
- email.address@example.com
One-click request via HTTPS POST
This is an illustration. Mailbox providers decide whether to display an unsubscribe button based on authentication, reputation and their own checks.
Best practices
- Process a valid one-click HTTPS POST without a login, CAPTCHA, redirect or additional confirmation. Repeated requests should be harmless.
- Cover both unsubscribe headers with a valid DKIM signature. Add the headers before signing the message.
- Keep a clearly visible unsubscribe link in the email body as well. A normal browser visit can show a confirmation page; do not unsubscribe on a GET request, which a link scanner may make.
- Use unguessable tokens or authenticated encryption to protect recipient details and prevent forged requests. A signature alone does not hide the data in a URL.
- Process requests promptly. Yahoo requires bulk senders to honour unsubscribes within two days. Ensure the recipient is removed from the relevant mailing before sending again.
- Ask your email service provider, such as AuthSMTP, for help adding and signing the headers.
References: RFC 8058, Gmail sender guidelines and Yahoo sender requirements.
Questions about an email you received
Who manages the mailing list?
The sender manages its own list and is responsible for removing your address. AuthSMTP provides email delivery services.
Why might this domain appear in an email?
An email can identify a separate website for unsubscribe requests. This domain belongs to AuthSMTP's unsubscribe project. The presence of a link alone does not verify that an email is genuine.
Can I unsubscribe from this page?
No. This page provides information and examples. Use the unsubscribe option in the original email or contact its sender.
What if unwanted emails continue?
Contact the sender and tell them which email address is receiving the messages. You can also block the sender or report unwanted mail using your email provider's controls.