How do I add an unsubscribe button to the email header and what is RFC 8058?
Michael Ko
Co-founder & CEO, Suped
Published 22 Apr 2025
Updated 17 Aug 2025
7 min read
As email sending evolves, so do the expectations of recipients and mailbox providers. One of the most significant shifts in recent years has been the push for easier unsubscribe options, particularly the prominent unsubscribe button that often appears in the email header, next to the sender's name. This change directly impacts how users interact with your emails and, crucially, your overall email deliverability.
For bulk senders, compliance with these new standards isn't just a recommendation, it's becoming a necessity. Major mailbox providers like Gmail and Yahoo have outlined clear requirements for implementing one-click unsubscribe mechanisms. These mandates are a direct response to recipient frustration with difficult or non-existent unsubscribe options, which often lead to emails being marked as spam. I've found that these changes are crucial for maintaining a healthy sender reputation.
At the heart of this one-click unsubscribe functionality is RFC 8058, a technical standard that defines how email clients can signal an intent to unsubscribe directly from the email header, without requiring the user to open the email or navigate to a landing page. This article will explain how to add this vital unsubscribe button to your email headers and dive into the specifics of RFC 8058.
Understanding the email header unsubscribe
The unsubscribe button in the email header is facilitated by the `List-Unsubscribe` header field. This isn't a new concept, as the original List-Unsubscribe header has been around for some time, typically allowing for mailto and HTTP links. However, modern requirements, especially from major inbox providers, favor a more direct and instantaneous method of opting out.
This header is a critical component for deliverability because it gives recipients an easy, visible way to opt out without having to mark your email as spam. When a user marks an email as spam, it significantly harms your domain reputation and can lead to your emails consistently landing in the junk folder or even being blocklisted (or blacklisted). A visible unsubscribe option reduces the likelihood of this negative action, turning a potential complaint into a clean unsubscribe.
Mailbox providers often display this unsubscribe link in a prominent position, such as near the sender's email address or subject line. This placement is dynamic and depends on the email client, but it's always outside the body of the email itself. Providing this option demonstrates a commitment to good email practices and user choice, which is highly valued by ISPs and ultimately contributes to better deliverability rates.
Header Field
Description
Example
List-Unsubscribe
Traditional unsubscribe method, usually a mailto link or HTTP URL.
Signals support for one-click unsubscribe via a POST request to the HTTP URL in List-Unsubscribe.
List-Unsubscribe=One-Click
What is RFC 8058 and its importance?
RFC 8058, officially titled "Signaling One-Click Functionality for List Email Headers," is the internet standard that revolutionized the unsubscribe process. Published in 2017, it provides a specific, standardized method for senders to include a one-click unsubscribe option directly within the email header. This means users don't have to navigate to a webpage, fill out a form, or even confirm their unsubscribe intent. One click, and they're unsubscribed.
The core of RFC 8058 lies in the interaction of two specific email headers: `List-Unsubscribe` and `List-Unsubscribe-Post`. The `List-Unsubscribe` header contains a URL (and optionally a mailto address) where the unsubscribe request should be sent. The crucial addition by RFC 8058 is the `List-Unsubscribe-Post` header, which, when set to `List-Unsubscribe=One-Click`, tells the email client to perform an HTTP POST request to the URL specified in the `List-Unsubscribe` header. This POST request is what enables the true one-click functionality, bypassing intermediate steps.
Implementing RFC 8058 correctly is vital because it significantly improves the user experience and, consequently, reduces the likelihood of recipients marking your emails as spam. For a detailed technical specification, I recommend consulting the official RFC 8058 documentation. It's worth noting that the URL provided in the `List-Unsubscribe` header must use HTTPS for security.
For most senders, adding the necessary unsubscribe headers for RFC 8058 compliance is handled by your Email Service Provider (ESP). Modern ESPs have integrated this functionality to ensure their users meet industry standards. However, it's always a good practice to verify that these headers are correctly configured in your outgoing emails, especially if you're a large-volume sender.
On your end, the primary responsibility lies in ensuring that the URL provided in the `List-Unsubscribe` header is a functional endpoint that can process a POST request. When an email client sends this POST request, your system must immediately and silently unsubscribe the user without any further interaction. This backend processing is critical for the one-click experience to work as intended.
For those who manage their own email infrastructure or use an ESP that requires manual configuration, you'll need to work with your development team to set up the endpoint. This involves creating a specific URL that listens for incoming POST requests and then updates your subscriber database to mark that email address as unsubscribed. It's also vital to return a 2xx success status code to the client after processing the unsubscribe request.
Key technical considerations
Secure URL: The unsubscribe URL in the header must use HTTPS.
POST request handling: Your server must be able to receive and process HTTP POST requests to the unsubscribe URL.
Immediate unsubscribe: The unsubscribe should occur immediately upon receiving the POST request, without any confirmation or additional clicks.
Success response: Return a 2xx status code to indicate successful processing.
Impact on deliverability and compliance
The primary drivers for widespread RFC 8058 adoption are the new sender requirements from Google and Yahoo. As of early 2024, bulk senders are explicitly required to implement one-click unsubscribe for promotional emails. Failure to comply can lead to significant deliverability issues, including emails being routed to the spam folder, delayed delivery, or even outright rejection.
Beyond compliance, implementing one-click unsubscribe is a best practice for maintaining a positive sender reputation. When recipients can easily opt out, they are less likely to hit the spam button out of frustration. Reduced spam complaints directly improve your sender reputation with mailbox providers, leading to better inbox placement for your legitimate emails. This proactive approach helps avoid being placed on email blocklists (or blacklists).
Ultimately, offering a seamless unsubscribe experience reflects well on your brand and fosters trust with your audience. It shows respect for their inbox and preferences, which can lead to higher engagement from those who choose to remain subscribed. This positive interaction contributes to a healthier email program and better long-term deliverability.
Without one-click unsubscribe
User experience: Requires finding a link in the email body, navigating to a page, and potentially multiple clicks or confirmations.
Complaint rates: Higher likelihood of recipients marking emails as spam due to frustration or difficulty unsubscribing.
Deliverability impact: Increased spam complaints negatively affect sender reputation, leading to more emails landing in spam or being blocked.
With RFC 8058 one-click unsubscribe
User experience: Simple, immediate opt-out with a single click in the email client interface.
Complaint rates: Reduced spam complaints as users have a clear, easy alternative to marking as junk.
Deliverability impact: Improved sender reputation and better inbox placement due to lower complaint rates and compliance.
Embracing the one-click future
As an email deliverability expert, I've seen firsthand how crucial effective unsubscribe mechanisms are. It's not just about compliance, it's about building trust and ensuring your emails reach their intended audience. The transition to one-click unsubscribe via RFC 8058 is a significant step forward for the email ecosystem.
Embracing this standard helps you meet the stringent requirements of major mailbox providers and also cultivates a healthier relationship with your subscribers. By prioritizing user experience, you not only improve your email deliverability but also reduce the chances of your domain being flagged for abusive sending practices. This ultimately leads to more effective and sustainable email marketing campaigns.
Views from the trenches
Best practices
Ensure your ESP fully supports RFC 8058, as they are primarily responsible for implementing the necessary headers and handling the POST requests.
Regularly monitor your email headers to confirm that the List-Unsubscribe and List-Unsubscribe-Post fields are correctly formatted and present in your outgoing emails.
Verify that your unsubscribe endpoint can process a POST request silently and immediately, without requiring any additional user interaction.
Prioritize HTTPS for your unsubscribe URL to ensure secure communication and compliance with modern standards.
Common pitfalls
Assuming your ESP automatically handles RFC 8058 compliance without verifying it, leading to missed requirements.
Using a mailto-only List-Unsubscribe header, which doesn't support true one-click functionality required by major providers.
Directing users to a landing page that requires multiple clicks or confirmation steps, defeating the purpose of one-click unsubscribe.
Not having a functional backend endpoint to process the POST request, causing unsubscribe failures.
Expert tips
Test your one-click unsubscribe functionality thoroughly across various email clients to ensure it works as expected.
Educate your marketing team on the importance of the header unsubscribe to understand its role in deliverability.
Consider a preference center for those who want to manage subscriptions instead of a full unsubscribe.
Stay updated on sender requirements from major mailbox providers, as these standards evolve.
Marketer view
Marketer from Email Geeks says the unsubscribe button in the email header is indeed what Yahoo and Gmail are referring to when they talk about a single unsubscribe option.
2024-01-18 - Email Geeks
Expert view
Expert from Email Geeks says the unsubscribe button in the email header is facilitated by RFC 8058.
Gmail and 
Yahoo have outlined clear requirements for implementing one-click unsubscribe mechanisms. These mandates are a direct response to recipient frustration with difficult or non-existent unsubscribe options, which often lead to emails being marked as spam. I've found that these changes are crucial for maintaining a healthy sender reputation.
