What are the requirements for List-Unsubscribe headers to comply with Yahoo and Gmail?
Matthew Whittaker
Co-founder & CTO, Suped
Published 21 Jun 2025
Updated 19 Aug 2025
8 min read
Navigating the complexities of email deliverability often feels like walking a tightrope, especially with the ever-evolving requirements from major mailbox providers. One area that has recently taken center stage is the List-Unsubscribe header. Gmail and Yahoo have introduced new mandates for bulk senders, making robust unsubscribe mechanisms a critical factor for successful inbox placement.
These updates aim to create a safer, less spammy email ecosystem for users. For us as senders, it means ensuring our List-Unsubscribe headers are configured correctly to support a seamless, one-click unsubscribe experience. Failing to meet these standards can significantly impact your email program, leading to messages being blocked (or blacklisted) or routed directly to spam folders.
The evolution of unsubscribe mechanisms
Historically, the List-Unsubscribe header allowed for two primary methods of unsubscribing: a mailto: link that would compose an email to an unsubscribe address, or a URL-based link that would direct users to a webpage to complete the process. While both offered a path to opt-out, the process often involved multiple steps, which could be frustrating for recipients.
The industry, driven by major providers like Google (Gmail) and Yahoo, has moved towards a more direct and user-friendly approach: one-click unsubscribe. This is standardized by RFC 8058, which outlines a non-interactive, in-application unsubscribe method.
This modern standard requires not just the presence of a List-Unsubscribe header, but a specific implementation. It demands that the unsubscribe action can be completed with a single click, without requiring the user to visit a webpage, log in, or confirm their decision. This significantly improves the user experience and reduces the likelihood of spam complaints.
The shift to this method is a direct response to consumer demand for greater control over their inboxes and a proactive step by mailbox providers to combat unwanted email. For senders, embracing this change is not just about compliance, but also about maintaining a positive sender reputation and ensuring your messages reach the inbox.
Key requirements for compliance with List-Unsubscribe headers
To fully comply with Gmail and Yahoo's new requirements, senders must implement both the List-Unsubscribe and List-Unsubscribe-Post headers. These headers work in tandem to facilitate the one-click unsubscribe process as defined by RFC 8058. The List-Unsubscribe-Post header specifically signals that a POST request should be sent to the provided URL.
It's not enough to simply include the headers. The URL specified in the List-Unsubscribe header must use HTTPS. This ensures the security and integrity of the unsubscribe request, protecting both the sender and the recipient from potential abuses. Using an HTTP URL will result in non-compliance, even if the unsubscribe technically functions.
HTTPS is mandatory for compliance
If your List-Unsubscribe header points to an HTTP URL instead of HTTPS, your email traffic will not be considered compliant with the RFC 8058 one-click unsubscribe standard. This can lead to penalties and impact your deliverability, regardless of whether the unsubscribe link technically works for the user.
Furthermore, both the List-Unsubscribe and List-Unsubscribe-Post headers must be covered by your DKIM signature. DKIM (DomainKeys Identified Mail) authentication helps verify the integrity of your email headers and content, assuring mailbox providers that the unsubscribe links haven't been tampered with since they were sent.
Understanding one-click unsubscribe mechanics
The essence of one-click unsubscribe, as enforced by Gmail and Yahoo, is to simplify the opt-out process for the recipient. When a user clicks the unsubscribe button often displayed prominently in the email client interface, the client sends a POST request to the URL specified in your headers. Your server then processes this request immediately, unsubscribing the user without further interaction.
This method differs from the traditional in-message unsubscribe link, which typically requires clicking a link within the email body, navigating to a landing page, and potentially confirming the unsubscribe. While you should still include a visible in-message unsubscribe link to comply with regulations like CAN-SPAM, the List-Unsubscribe header provides an additional, more streamlined option for users.
Some senders have worried that Yahoo might restrict the POST method to only trusted senders. However, the requirement for RFC 8058 one-click unsubscribe is universal for bulk senders. Yahoo's documentation indicates that implementing a functioning List-Unsubscribe header that supports one-click is a standard expectation for marketing and subscribed messages.
Therefore, regardless of your sending volume or current reputation, it's crucial to correctly configure these headers. The goal is to make unsubscribing as easy as possible for all recipients. This proactive approach helps build trust with mailbox providers and maintains a healthy sending relationship, reducing the likelihood of your emails being caught by spam filters or your domain ending up on a blacklist (or blocklist).
Impact on deliverability and compliance
Failing to meet these new List-Unsubscribe header requirements can have significant negative consequences for your email program. Mailbox providers like Gmail and Yahoo have stated they will enforce these standards, meaning non-compliant messages may experience reduced deliverability, increased spam placement, or even outright rejection.
Beyond technical compliance, a properly configured List-Unsubscribe header plays a crucial role in managing your spam complaint rates. When users can easily unsubscribe via the email client's interface, they are less likely to mark your emails as spam. This helps keep your complaint rate below the crucial 0.3% threshold set by Gmail.
Old approach: manual unsubscribe
Multi-step process: Often redirects to a webpage, requiring additional clicks or form submissions.
User frustration: Can lead to higher spam complaints when users find it difficult to opt-out.
Compliance risk: May not fully satisfy the spirit of CAN-SPAM or GDPR requirements for easy unsubscribing.
New approach: one-click unsubscribe
Instant opt-out: Single action, often handled directly by the email client.
Reduced spam complaints: Provides a straightforward way out, improving sender reputation.
While List-Unsubscribe headers are key for client-side unsubscribe options, remember that federal laws like CAN-SPAM (Controlling the Assault of Non-Solicited Pornography And Marketing Act) also mandate a clear and conspicuous unsubscribe mechanism within the email body. The List-Unsubscribe header complements, but does not replace, this legal requirement. Ensure both are correctly implemented for comprehensive compliance and optimal email performance.
The path to better inbox placement
Adhering to the List-Unsubscribe header requirements from Gmail and Yahoo is more than just ticking a box; it's a fundamental shift towards user-centric email practices. By providing an effortless one-click unsubscribe experience, you demonstrate respect for your recipients' preferences. This positive interaction can significantly reduce spam complaints and improve your overall domain reputation.
As mailboxes continue to tighten their anti-spam measures, proactive compliance with standards like RFC 8058 will differentiate legitimate senders from those at risk. Consistently meeting these expectations helps build a strong sending reputation, which is the cornerstone of excellent email deliverability.
Regularly verify your List-Unsubscribe header configuration and monitor your email performance. Staying vigilant and adaptable to these evolving standards will ensure your messages continue to reach their intended audience, fostering engagement and positive sender-recipient relationships.
Example of compliant List-Unsubscribe headers (for bulk email)HTTP
Ensure your unsubscribe URL is HTTPS and can process a POST request for instant one-click unsubscribes.
Cover both List-Unsubscribe and List-Unsubscribe-Post headers with your DKIM signature for authentication.
Offer a visible, in-message unsubscribe link in addition to the header method to comply with legal requirements.
Regularly test your unsubscribe process to confirm it is functioning as expected and meets all current standards.
Common pitfalls
Using HTTP instead of HTTPS for your List-Unsubscribe URL will lead to non-compliance and deliverability issues.
Failing to cover List-Unsubscribe headers with your DKIM signature can cause authentication failures and trust issues.
Relying solely on the List-Unsubscribe header without an in-message link can violate anti-spam laws like CAN-SPAM.
Not honoring unsubscribe requests within the required two-day timeframe will severely damage your sender reputation.
Expert tips
Proactively implement RFC 8058 one-click unsubscribe to improve user experience and reduce spam complaints.
Prioritize a secure, single-step unsubscribe method over multi-step processes for better deliverability.
Stay informed on postmaster guidelines, as requirements for email headers and unsubscribe methods can evolve.
Understand that client-side unsubscribe features are a bonus, not a replacement for legal unsubscribe obligations.
Marketer view
Marketer from Email Geeks says they are concerned if only having a URL-based List-Unsubscribe header is sufficient, or if they need to include a mailto: link as well to avoid being flagged by Yahoo and Gmail. They also heard a rumor that Yahoo might only allow trusted senders to use the unsubscribe POST method and want to know if that means smaller senders are at a disadvantage.
2023-11-22 - Email Geeks
Expert view
Expert from Email Geeks says senders must have a non-interactive, in-application unsubscribe method, which can be either a List-Unsubscribe header with a mailto: URL or, preferably, an RFC 8058 List-Unsubscribe-Post header. This also requires supporting infrastructure like DKIM authentication, an HTTPS link in the List-Unsubscribe header, and a server capable of handling POST requests.
2023-11-22 - Email Geeks
Achieving and maintaining compliance
For email senders, meeting the List-Unsubscribe header requirements from Gmail and Yahoo is no longer optional. These are fundamental shifts designed to improve user experience and reduce unwanted email. Implementing RFC 8058 for one-click unsubscribe, using HTTPS for your unsubscribe URL, and ensuring DKIM covers these headers are all critical steps.
By proactively adopting these best practices, you not only ensure compliance but also strengthen your sender reputation and improve the likelihood of your emails reaching the inbox. This commitment to a better email experience benefits everyone, from the senders who see higher engagement to the recipients who enjoy a cleaner inbox.
Yahoo have introduced new mandates for bulk senders, making robust unsubscribe mechanisms a critical factor for successful inbox placement.
Google (Gmail) and 
Yahoo, has moved towards a more direct and user-friendly approach: one-click unsubscribe. This is standardized by RFC 8058, which outlines a non-interactive, in-application unsubscribe method.
Gmail and 
Yahoo, is to simplify the opt-out process for the recipient. When a user clicks the unsubscribe button often displayed prominently in the email client interface, the client sends a POST request to the URL specified in your headers. Your server then processes this request immediately, unsubscribing the user without further interaction.
