What are the top email deliverability best practices for Yahoo and shared DKIM domains?

Key findings

• Authentication is paramount: Proper email authentication using SPF, DKIM, and DMARC is fundamental for Yahoo and other mailbox providers. These protocols verify sender identity and reduce spam, significantly impacting inbox placement. You can learn more about setting up these protocols by reviewing our guide on best practices for SPF, DKIM and DMARC.
• Audience engagement: Sending emails that recipients want and expect, coupled with active engagement management, is critical for maintaining a positive sender reputation and avoiding the spam folder. This involves ensuring your list is opt-in and regularly removing unengaged subscribers.
• Shared DKIM considerations: While shared DKIM domains can be part of an email setup (often for FBLs), their impact on deliverability can be a concern, particularly with Gmail. If a shared DKIM domain is associated with spammy behavior from other users, it can negatively affect your mail. It's important to understand how individual versus shared DKIM affects deliverability.
• Double signing: For best results, it's recommended to double sign your emails, meaning you sign with both your own DKIM domain (which aligns with your 'From' address) and any shared DKIM domain used by your Email Service Provider (ESP). The aligned DKIM domain carries significantly more weight in deliverability decisions.

Key considerations

• Sender reputation management: Actively monitor and maintain your sender reputation. Poor reputation, whether due to shared IP space or shared DKIM domains, can lead to widespread blocking or bulk-foldering of your emails.
• Provider choice matters: If a provider's shared DKIM or IP space consistently has a bad reputation, consider evaluating alternative solutions. Sometimes, fundamental issues with a provider's client management or infrastructure can undermine your deliverability efforts.
• Yahoo's specific guidelines: Refer directly to Yahoo's sender best practices for the most up-to-date and specific requirements.

Key opinions

• Audience focus: The most critical factor for deliverability is sending content that people genuinely want and to recipients who explicitly desire to receive it. This general principle applies universally across all mailbox providers, including Yahoo.
• List hygiene: Marketers stress the importance of sending only to opt-in traffic and actively managing engagement to maintain list health. A clean list reduces bounces and spam complaints, improving overall sender reputation.
• Authentication basics: While specific to Yahoo, marketers universally acknowledge that properly authenticating emails is a fundamental first step for deliverability to any provider.
• Shared DKIM and Gmail: Some marketers express more concern about shared DKIM domains affecting deliverability with Gmail than with Yahoo, noting Gmail's increased likelihood to bulk or block if spammy behavior is associated with that shared domain. This underscores the need to understand why emails go to spam.

Key considerations

• Engagement tracking: Regularly monitor recipient engagement metrics (opens, clicks, unsubscribes, complaints) to identify and address issues early. Low engagement can signal deliverability problems.
• Segmentation and relevance: Focus on sending personalized and relevant content to segmented audiences to improve engagement and reduce the likelihood of messages being marked as spam. This approach helps how email sending practices impact domain reputation.
• Staying informed: Marketers need to stay updated on new requirements from major mailbox providers like Yahoo and Google, as these policies can rapidly change the landscape of email deliverability. Kinsta's blog on Gmail and Yahoo Mail requirements is a good resource.

Key opinions

• Double signing best practice: Experts recommend 'double signing' emails, meaning signing with both your own aligning DKIM domain and any shared DKIM domain. This dual authentication provides stronger verification for receiving servers.
• Shared DKIM and Gmail's strictness: A common concern among experts is Gmail's stricter approach to shared DKIM domains compared to Yahoo. If a shared domain is used for spam, Gmail is more likely to block or bulk mail, impacting all senders on that domain. This highlights the importance of understanding DMARC reports from Google and Yahoo.
• Aligned DKIM's weight: The DKIM domain that aligns with your 'From' address carries significantly more weight in deliverability decisions than a non-aligned or shared DKIM domain. Therefore, ensuring your primary domain is well-reputed and properly authenticated is paramount.
• Provider accountability: If a shared DKIM domain or shared IP space is consistently problematic due to other users, it indicates a failure on the part of the provider to effectively manage their client base and remove bad actors. This can be as critical as what happens when your IP gets blocklisted.

Key considerations

• Strategic switching: If a shared DKIM domain consistently leads to deliverability issues, even with double signing, it may be necessary to consider switching to a different email service provider (ESP) or a more dedicated sending solution.
• Reputation management beyond defaults: Simply opting out of default shared settings from providers may not be enough if the overall reputation of the shared domain or IP space is inherently poor. A proactive stance on sender reputation is required.
• Impact of shared resources: The behavior of other senders using the same shared DKIM key or IP space can directly affect your deliverability. If a large percentage of traffic from that shared key is bad, it will inevitably impact your mail, regardless of your individual sending practices.
• Continuous monitoring: Constant vigilance over your deliverability metrics and sender reputation (including checking for blocklistings) is essential. Tools like Google Postmaster Tools can help monitor performance with major providers, as discussed in the MailPoet blog on new sender requirements.

Key findings

• Strong authentication required: Yahoo and Gmail both mandate strong email authentication using SPF, DKIM, and DMARC. These records are essential for verifying sender identity and combating impersonation and spam. Further details on this are available in our guide on DMARC, SPF, and DKIM.
• Low spam complaint rates: Senders must maintain a very low spam complaint rate, typically below 0.3%. High complaint rates signal unwanted mail and can lead to severe deliverability issues, including blacklisting (or blocklisting).
• One-click unsubscribe: To facilitate recipient preference management, a one-click unsubscribe mechanism is increasingly required. This makes it easy for users to opt out, reducing spam complaints and improving sender reputation.
• Relevant and wanted messages: Mailbox providers emphasize that messages should be relevant and wanted by recipients. This speaks to the importance of explicit consent, accurate segmentation, and valuable content, all contributing to positive engagement and better inbox placement.

Key considerations

• DMARC policy: Implementing DMARC authentication with at least a neutral policy (like p=none) is crucial. DMARC helps prevent email impersonation and ensures that emails are properly authenticated. Learn more in our simple DMARC examples.
• SPF and DKIM alignment: For SPF, the Return-Path domain should align with the 'From' domain. For DKIM, the d= domain should align with the 'From' domain. Non-alignment can negatively impact deliverability.
• Monitoring postmaster tools: Utilize postmaster tools provided by Yahoo and Google to monitor your sending reputation, spam rates, and authentication status. These tools offer crucial insights into your email program's performance.
• Compliance with new rules: As demonstrated by the recent 2024 Gmail and Yahoo sender requirements, mailbox providers are continually updating their policies. Senders must proactively adapt to these changes to maintain deliverability. The FluentCRM article on Google and Yahoo's new rules provides context.