Summary
Verifying Sendlane's compliance with RFC 8058 for one-click unsubscribe involves a multi-faceted approach. Experts, marketers, and documentation all point to the importance of checking for the presence and correct formatting of the List-Unsubscribe header (with both mailto: and https: options). Key methods include manual header inspection, using email testing tools, and sending test emails to various clients to check for the unsubscribe link's presence. It's also vital to ensure Sendlane handles unsubscribe requests properly, and the absence of a one-click unsubscribe option in Gmail could indicate an issue. Adherence to Google's Postmaster Tools guidelines is also critical. Escalating concerns with Sendlane support can help clarify their implementation status.
Key findings
- List-Unsubscribe Header: The presence and correct formatting of the List-Unsubscribe header are fundamental.
- Testing Tools: Email testing tools offer a reliable method for inspecting headers.
- Gmail Indicator: The presence or absence of a one-click unsubscribe link in Gmail can be a quick indicator.
- Google Compliance: Adherence to Google Postmaster Tools guidelines is crucial for deliverability.
Key considerations
- Escalation: Consider escalating the issue with Sendlane support for clarification.
- Hidden Blocking: There is a possibility Sendlane might be silently blocking requests.
- Functionality: The functionality of both mailto and HTTP unsubscribe mechanisms should be tested.
- Comprehensive Testing: Testing should be performed across different email clients.
What email marketers say
8 marketer opinions
To verify Sendlane's compliance with RFC 8058 for one-click unsubscribe, email marketers recommend several approaches. These include escalating concerns with Sendlane support, as proper implementation requires both an unsubscribe link in the footer and a List-Unsubscribe header. Additionally, it's suggested to use email testing tools to inspect email headers for correct formatting of the List-Unsubscribe header. Manually inspecting email headers in email clients and viewing the source code of test emails are also viable methods. The presence of an unsubscribe link in the header or body of test emails sent to various email clients can also indicate compliance. Google's Postmaster Tools compliance is also a key consideration.
Key opinions
- Escalate Support: Escalating the issue with Sendlane support can provide clarity on their RFC 8058 implementation status.
- Header Inspection: Email testing tools and manual header inspection can confirm the presence and correct formatting of the List-Unsubscribe header.
- Test Emails: Sending test emails and checking the header is the easiest approach.
- Google Compliance: Complying with Google Postmaster Tools guidelines for one-click unsubscribe is critical.
Key considerations
- Silent Blocking: Sendlane might be silently blocking requests to the unsubscribe endpoint.
- GPT Check: Google Postmaster Tools (GPT) may flag emails if they are bulk emails without the one-click unsubscribe.
- Correct Formatting: Ensure the List-Unsubscribe header is correctly formatted with a valid URL or mailto: address.
- Visual Indicator: Check for the presence of an unsubscribe link in the header or body as a visual indicator of compliance.
Marketer view
Email marketer from Reddit shares to manually inspect an email sent from Sendlane, viewing the message headers to verify the List-Unsubscribe header is present and correctly formatted with a valid URL or mailto: address. Check the HTML body for a visible unsubscribe link, per RFC 8058.
21 Nov 2023 - Reddit
Marketer view
Email marketer from Stack Overflow explains that you can view the raw email headers to check for List-Unsubscribe headers. They suggest viewing the email source in your email client and searching for the relevant headers.
22 May 2025 - Stack Overflow
What the experts say
4 expert opinions
Experts suggest several methods to check if Sendlane complies with RFC 8058 for one-click unsubscribe. These involve inspecting email headers for the presence of List-Unsubscribe headers, including List-Unsubscribe-Post, and verifying that both the List-Unsubscribe header with an HTTPS link and the DKIM-Signature header are included. Furthermore, it's essential to validate that the unsubscribe mechanisms (mailto or HTTP) function correctly. Finally, the absence of a one-click unsubscribe link in Gmail may indicate non-compliance.
Key opinions
- Header Presence: Presence of List-Unsubscribe and List-Unsubscribe-Post headers indicates attempted support.
- Header Validation: Confirm HTTPS link and DKIM-Signature inclusion in relevant headers.
- Functionality Testing: Validate unsubscribe mechanisms (mailto/HTTP) are correctly processing unsubscribe requests.
- Gmail Indicator: Absence of a one-click unsubscribe link in Gmail might suggest an implementation problem.
Key considerations
- POST Endpoint: Need to check the POST endpoint to ensure it's functioning correctly.
- Incorrect Implementation: If Google flags the link as non-compliant and Sendlane's explanation is incorrect, the implementation is likely flawed or non-existent.
- Essential but Insufficient: Presence of a List-Unsubscribe header is necessary but not enough; proper functionality must be validated.
Expert view
Expert from Email Geeks suggests if Google says the link isn't compliant, and Sendlane is explaining "one click unsubscribe" so incorrectly, then it's very likely they haven't implemented it at all or it's implemented incorrectly.
28 Jun 2022 - Email Geeks
Expert view
Expert from Word to the Wise discusses that in Gmail, a one-click unsubscribe link is displayed at the top of the email if the sender has correctly implemented the List-Unsubscribe header. If Sendlane emails do not show this link in Gmail, it suggests a problem with their implementation.
27 Mar 2025 - Word to the Wise
What the documentation says
4 technical articles
Documentation emphasizes that complying with RFC 8058 involves including a List-Unsubscribe header with either a mailto: or https: URL in the email header. Guidelines from Google Postmaster Tools require bulk senders to have one-click unsubscribe functionality with a prominent and accessible link. Regular audits and email testing tools are recommended to ensure correct setup and functioning of List-Unsubscribe headers.
Key findings
- RFC 8058 Standards: RFC 8058 mandates the inclusion of a List-Unsubscribe header with mailto: or https: URL.
- Header Presence: A List-Unsubscribe header must be included in the email header.
- Google Requirements: Google Postmaster Tools requires a prominent and accessible unsubscribe link for bulk senders.
- Auditing and Testing: Regular audits and testing tools are recommended to ensure proper setup and function.
Key considerations
- Implementation Methods: RFC 8058 defines specific methods for handling unsubscribe requests that must be implemented.
- Header Versions: Check for both mailto: and HTTP versions of the List-Unsubscribe header.
- Accessibility: The unsubscribe link should be prominent and easily accessible, adhering to Google's specifications.
- Regular Checks: Regularly audit configurations and use testing tools to ensure compliance with one-click unsubscribe standards.
Technical article
Documentation from Litmus explains that a List-Unsubscribe header must be included in the email's header to facilitate one-click unsubscribe. It advises checking for both the mailto: and HTTP versions of the header.
28 Mar 2022 - Litmus
Technical article
Documentation from Google Postmaster Tools outlines the guidelines for bulk senders, which includes requiring one-click unsubscribe functionality. To verify compliance, check if Sendlane includes a prominent and easily accessible unsubscribe link that adheres to Google's specifications.
7 Mar 2022 - Google
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