In February 2024, Gmail and Yahoo implemented new email-sending standards focusing on three critical areas: Authentication, One-Click Unsubscribe, and Low Spam Complaints. These changes push large-scale senders to own up to their sending practices and ensure that the emails they send are interesting and relevant to receivers. The impact of these guidelines will become even more prominent by June 2024, as failing to adhere to them or having higher spam complaints will have significant consequences. While this initiative began with Gmail and Yahoo, other mailbox providers like Microsoft are expected to follow suit. By understanding and adhering to these new guidelines, senders can maintain a strong reputation and enhance their email deliverability. 

Authentication is key

Set up SPF and DKIM email authentication for your domain: This helps mailbox providers recognize the authority of your domain and assign a reputation to it. Gmail recommends using a 2048-bit DKIM key for enhanced security.    

DMARC policy is now mandatory for large senders. DMARC tells mailbox providers what to do with emails that do not pass authentication. It helps mailbox providers act on such emails, and they can alert you when someone tries to spoof your domain. This helps in safeguarding the reputation. A “none” policy is acceptable for now.

Simplify unsubscribing: Unsubscribing should be easy: letting go of users who are not interested in your email improves positive engagement and reputation. Implementing a one-click list-unsubscribe header is not just a best practice, but  a must.  This helps Gmail and Yahoo to automatically trigger unsubscribe requests when users click "Report Spam."

Keep spam complaints as low as possible: Gmail postmaster tools report spam complaints with daily frequency. Senders must track and keep spam complaints below 0.1% ideally and never cross 0.3%. Spam complaints are the direct indicator of whether your emails are relevant for your users or if they’re not interested. 

These updates, the first of more to come, aim to create a safe and secure email experience for users by cracking down on spam and ensuring senders deliver relevant emails. They also improve deliverability and user trust. 

Understanding these changes

From an email infrastructure point of view, email service providers have always offered senders two options for dispatching emails: dedicated pools and shared pools. Dedicated pools function similarly to exclusive access areas, reserved solely for established brands with a demonstrably positive email reputation. Within these dedicated pools, authentication protocols are rigorously adhered to, streamlining the process for all senders.

Shared pools, however, present a unique challenge for email service providers and mailbox providers. Initially conceived to assist smaller senders – often characterized by low volume or sporadic campaigns – shared pools aimed to enhance their overall deliverability rates. 

Unfortunately, over time, senders with questionable practices, often referred to as ‘gray senders,’ began to exploit the anonymity afforded by shared pools. This exploitation served to obfuscate their poor sending habits, significantly complicating reputation management efforts for mailbox providers.

The recently implemented changes mandate that any sender transmitting more than 5,000 emails per day must establish and maintain their independent reputation. Consequently, high-volume senders will no longer be able to leverage the anonymity of shared pools to obscure their email traffic. 

While this may not represent the sole impetus for guideline modifications, it undoubtedly constitutes a prominent area of impact from the standpoint of email service providers.

What is the impact?

One of the biggest challenges associated with the new guidelines is the potential for stricter parsing rules and new error messages. Senders who are unable to comply with the guideline changes will likely experience negative impacts on both email delivery and sender reputation.

Authentication failure in email setup can trigger error messages, hindering email deliverability. These messages, also known as error codes, bounce codes, or Delivery Status Notifications (DSN), act as the digital red flags that alert senders to delivery issues. Here's a breakdown of the error codes you might encounter:

Gmail error codes and troubleshooting

Here are some of the common Gmail error codes and messages resulting from issues related to DMARC, SPF, and DKIM, and their revised sender guidelines:

• 5.7.1: SPF or DKIM failure - This indicates that the email failed authentication checks. Review your SPF record and ensure it accurately reflects the authorized email servers allowed to send emails on behalf of your domain.
• 5.7.6: Sender address rejected - This error typically signifies a problem with the "From" address not being authorized by the domain it claims to originate from or a domain reputation issue. Double-check your SPF and DKIM configurations and your DKIM keys to ensure they are properly configured in your DNS records.
• 5.7.26 Temporary local problem: This could be caused by exceeding sending limits or temporary issues with your email server. However, consistent occurrences might indicate a problem with authentication or email content.
• 5.7.6 Unable to Relay: This error indicates an issue with the sending server's IP address being blacklisted. You'll need to contact your email service provider (ESP) to investigate.
• 5.7.8 Body Check Failed: This error suggests potential spam content within the email body. Analyze your content for spammy triggers and ensure compliance with Gmail's content guidelines.

When encountering a Gmail error message, the specific code and message are crucial. Here’s Gmail’s full list of errors and codes.

Yahoo Mail error codes and troubleshooting

Here are some common Yahoo Mail error codes related to authentication failures:

• 553 Authentication Failure: This error indicates an issue with SPF or DKIM authentication. Verify your SPF and DKIM records are configured correctly.
• 553 5.7.1 Sender address rejected: Similar to the Gmail error, this indicates a problem with the sender's email address or domain. Investigate your SPF and DKIM configuration.
• 554 5.7.0 Authentication failure: This is a general authentication failure message. Review your SPF, DKIM, and DMARC records for any inconsistencies.
• 554 Delivery Disallowed: This permanent error suggests a severe issue like repeated spam complaints or a blacklisted IP address. You need to contact the Yahoo Mail Postmaster for further investigation. Yahoo advises against resending an email that returns a 5xx error; consider implementing a policy for the removal of all email addresses that trigger such errors.

When receiving these error codes from Yahoo Mail, the specific code in the 5XX range provides valuable clues. Here’s Yahoo’s full list of error codes.

What actions should you take?

If you manage email traffic for multiple domains and haven't implemented authentication yet, prioritize authenticating your highest-quality traffic first. You can then gradually roll out authentication to the remaining traffic.

However, when many domains are sending emails through your infrastructure, some domains may fail authentication due to uncontrollable reasons, such as clients misconfiguring DNS settings. You need an email infrastructure solution intelligent enough to handle these cases effectively. At Halon, we have developed a powerful solution set that empowers large-scale senders to tackle the Yahoo and Gmail changes. Here are three solutions that help you manage this situation better.

The Halon advantage

• Proactive authentication check: This plugin safeguards your sending infrastructure's reputation by proactively verifying email authentication before delivery. Emails that fail authentication are placed in a separate queue to prevent negative impacts on your reputation. Additionally, you can configure actions for these failed emails, such as discarding them, sending alerts, or delivering them through a different infrastructure. This proactive approach protects your primary IP addresses and domains from potential reputation damage.

• Reactive error handling: With Halon Engage, you can parse authentication-related error messages in detail and manage emails falling into these queues separately. This empowers you to take actions like pausing delivery, raising flags, or notifying the customer.
• Per-domain/tenant queues: With Halon Engage, you are not only able to segment messages based on sending IP and destination, but also the sending domain or tenant ID. Thanks to this, delivery issues for one tenant does not cause queue line blocking for other tenants on the same shared sending IP.
• One-click unsubscribe: Halon facilitates a readily accessible unsubscribe option within your email headers, ensuring user convenience and compliance with unsubscribe regulations. It has a feature that automatically adds the necessary List-Unsubscribe header to your emails. 

The way forward: adapting and thriving

The future of email sending requires a focus on user experience and email security. Adapting to the new Yahoo and Gmail sender guidelines has become crucial for any business that relies on email marketing. Non-compliance can result in significant email deliverability issues, potentially leading to frustrated customers and lost revenue.

However, these changes also present a great opportunity for thriving. While becoming compliant may require initial effort, the long-term benefits are undeniable. 

Future-proof your email sending with Halon - not only does it handle today's stricter guidelines, but it's also built to seamlessly integrate with potential future regulations.  In other words, with Halon, you're equipped to tackle email sending with confidence, now and into the future.

Click here to learn how Halon can help you stay on top of new email authentication guidelines, experience higher inbox placement, and create a more receptive audience for your messages.