How to resolve domain blocklisting and improve email reputation?

Key findings

• SORBS impact: Listings on blocklists like SORBS SPAM often have minimal impact, affecting less than 1% of email sends, due to their less stringent listing policies and limited widespread adoption by major inbox providers.
• Google's reputation matters most: A "Bad" reputation in Google Postmaster Tools is a far greater concern than a listing on a niche blocklist, indicating significant deliverability issues.
• Root cause focus: Identifying and addressing the underlying issues, such as poor list hygiene or problematic sending practices, is crucial for long-term reputation repair rather than just delisting.
• Policy and practices: Sustained improvements in email policies and sending practices are the most effective way to improve email deliverability and sender reputation, with specific audits for deliverability being beneficial.

Key considerations

• Prioritize major ISPs: Focus on resolving reputation issues with major inbox providers like Google and Microsoft first, as they govern the majority of email traffic.
• Delisting process: If you choose to seek delisting from a less impactful blocklist like SORBS, create an account on their website to understand the listing reason and follow their specific delisting procedure.
• Improve engagement: The primary "tool" for improving reputation with Google involves sending emails that elicit positive recipient engagement (opens, clicks, replies) to signal good intent to their machine learning filters. Read more about improving sender reputation in general.
• Address underlying issues: Never request delisting without first addressing the core issues that led to the listing, such as poor list hygiene or sending to unengaged contacts. Failing to do so can result in re-listing, making future delisting attempts more difficult.

Key opinions

• Focus on Google: The consensus among marketers is to prioritize addressing a "Bad" reputation with Google Postmaster Tools over less influential blocklists like SORBS. Google's reputation directly impacts inbox placement for a vast audience.
• List hygiene is paramount: Poor list hygiene is frequently identified as a primary cause of blocklistings and reputation issues, leading to spam trap hits and low engagement.
• Engagement drives reputation: Improving email engagement metrics (opens, clicks, replies) is highlighted as the most effective strategy for building a positive sender reputation with algorithmic filters.
• Beware of "snake oil" tools: Many marketers express skepticism about tools promising to fix deliverability without addressing underlying policy and practice issues, often labeling them as ineffective or a distraction.

Key considerations

• Identify root causes: Before attempting to delist or implement reputation-building strategies, marketers should identify the specific reasons for their poor reputation, such as sending to old, unengaged data or hitting spam traps.
• Educate leadership: It is often necessary to educate organizational leadership on email deliverability best practices and the long-term impact of sender reputation.
• Segment audiences: To improve engagement and avoid blocklists, marketers should segment their email audience, focusing on sending to regularly engaged users and gradually expanding their reach over time.
• Implement best practices: Key practices include maintaining a clean email list by regularly removing unsubscribed or unengaged contacts, using double opt-ins, and avoiding spam trigger words. Learn more about how to improve domain reputation.

Key opinions

• SORBS is often ignorable: Many experts consider SORBS to be a less critical blocklist, suggesting it's safe to ignore unless specific issues arise, partly due to its listing policies potentially leading to false positives.
• Google reputation is key: Experts widely agree that a bad reputation with Google is a far more pressing issue than being listed on a smaller blocklist.
• Practices over tools: The primary "tools" for improving deliverability are effective email policies and sending practices, with other reputation-fixing tools often dismissed as secondary or misleading.
• Engagement as a signal: For Google and similar algorithmic filters, the most effective method to build a good reputation is to send emails that encourage positive user interactions.

Key considerations

• Proactive delisting for SORBS: If you choose to address a SORBS listing, create an account on their site to understand the specific listing reason and proactively request delisting.
• Identify and address root causes: Always find the specific deliverability issues. For example, being listed on SORBS often correlates with sending to old, unengaged data which can also affect overall reputation.
• Segment and clean lists: Review segmentation practices. If sending to broad, unengaged lists, tighten them up. Do not request delisting from any blocklist without first making significant list changes, or you risk immediate re-listing.
• Implement authentication: Implement robust email authentication methods like SPF, DKIM, and DMARC to prevent spoofing and phishing, which can lead to blocklisting. This is a foundational best practice for deliverability as described by Mailgun in their best practices guide on avoiding email blocklists.

Key findings

• Authentication is foundational: Proper implementation of SPF, DKIM, and DMARC is fundamental for proving email legitimacy and preventing spoofing, which directly impacts domain reputation and blocklist avoidance. You can learn more about DMARC, SPF, and DKIM.
• Engagement metrics matter: Mailbox providers closely monitor recipient engagement (opens, clicks, replies) and negative signals (spam complaints, unsubscribes) as primary indicators of sender reputation.
• List quality is crucial: Sending to valid, active, and engaged email addresses minimizes bounce rates and spam trap hits, which are critical for maintaining a positive reputation.
• Consistency is key: Consistent sending volume and content type help mailbox providers establish a baseline for your sending behavior, making it easier to trust your emails.

Key considerations

• Monitor Postmaster Tools: Regularly check tools like Google Postmaster Tools to track your domain's reputation, including spam rate, IP reputation, and feedback loop data. Twilio's blog also describes ways to check your email sending reputation.
• Implement DMARC policies: Gradually move towards a DMARC policy of quarantine or reject to protect your domain from unauthorized use and improve trust with receiving servers. Learn about the benefits of implementing DMARC.
• Manage complaint rates: Keep spam complaint rates as low as possible, ideally below 0.1%, as high rates severely damage reputation and trigger filtering.
• Respect unsubscribe requests: Promptly process all unsubscribe requests to avoid sending to unwanted recipients, which contributes to spam complaints and poor sender standing.