What are the most important email blacklists to monitor and how do you check them?

Summary

Monitoring email blacklists is critical for maintaining good email deliverability. Spamhaus is consistently identified as the most important blacklist, with its SBL, ZEN, and DBL requiring understanding. SURBL, Barracuda, and URIBL are also key. Monitoring sender reputation is essential, using tools like Google Postmaster Tools, Microsoft SNDS, Sender Score, and Talos Intelligence. Blacklist checks can be performed using Spamhaus's BRC, Barracuda Central's lookup tool, MultiRBL, MXToolbox, and WhatIsMyIPAddress. Analyzing traffic and logs can reveal impacting blacklists. Maintaining good sending practices like consent and honoring unsubscribes is crucial. Understanding the specific removal process for each blacklist is essential for delisting. Evaluate blacklists based on their impact and relevance. Some lists, like Unsubscore, are considered less important.

Key findings

  • Top Blacklists: Spamhaus (SBL, ZEN, DBL), SURBL, Barracuda, and URIBL are frequently cited as critical for monitoring.
  • Monitoring Tools: Tools like MultiRBL, MXToolbox, WhatIsMyIPAddress, Google Postmaster Tools, Microsoft SNDS, Sender Score, Talos Intelligence, and BlacklistAlert are helpful for checking blacklist status and sender reputation.
  • Actionable Insights: Analyzing traffic, logs, and sender reputation provides actionable insights to identify and address deliverability issues.
  • Proactive Prevention: Maintaining good sending practices and proactively managing sender reputation are key to preventing blacklisting.
  • Importance of Spamhaus: Spamhaus is repeatedly emphasized as the most important blocklist to monitor.

Key considerations

  • Relevance Assessment: Focus monitoring efforts on blacklists that significantly impact your specific audience and email program.
  • Removal Procedures: Thoroughly understand and follow the specific delisting procedures for each blacklist.
  • Accurate Information: Ensure the information used for checking blacklists (e.g., hostnames) is up-to-date and accurate.
  • Holistic Approach: Adopt a holistic approach by combining blacklist monitoring with sender reputation management and good sending practices for optimal deliverability.
  • Understand blacklist impact: Understand the different impacts blacklists have on deliverability, some cause mail to be blocked where others are used as one of many data points in a decision.

What email marketers say
11Marketer opinions

Monitoring email blacklists is crucial for maintaining good email deliverability. Key blacklists to watch include Spamhaus, SURBL, Barracuda, and URIBL. Tools like MultiRBL.valli.org, MXToolbox, and WhatIsMyIPAddress allow for checking IPs and domains against multiple lists simultaneously. Sender Score and Talos Intelligence can help gauge sender reputation, while BlacklistAlert provides comprehensive blacklist monitoring and alerts. Analyzing traffic and checking logs helps identify the impact of specific blacklists on your email volume. Maintaining good sending practices, such as obtaining consent, using double opt-in, and honoring unsubscribe requests, is essential to avoid blacklisting.

Key opinions

  • Key Blacklists: Spamhaus, SURBL, Barracuda, and URIBL are frequently mentioned as critical blacklists to monitor.
  • Monitoring Tools: Tools like MultiRBL, MXToolbox, WhatIsMyIPAddress, Sender Score, and BlacklistAlert are useful for checking blacklist status and sender reputation.
  • Traffic Analysis: Analyzing traffic and logs can reveal which blacklists are impacting email volume.
  • Proactive Measures: Good sending practices, such as obtaining consent and honoring unsubscribe requests, are essential for avoiding blacklisting.

Key considerations

  • Impact Assessment: Understand how specific blacklists impact your email deliverability to prioritize monitoring efforts.
  • Tool Selection: Choose monitoring tools based on their ability to provide comprehensive blacklist checks and reputation insights.
  • Remediation: Have a plan in place to address blacklist listings promptly and effectively.
  • Sender Reputation: Continuously monitor and improve your sender reputation to prevent future blacklisting.
Marketer view

Email marketer from Reddit shares that being on major blacklists like Spamhaus can severely impact email deliverability. They respond that it's crucial to regularly check your IPs and domains against these lists and address any issues promptly to maintain a good sender reputation.

August 2024 - Reddit
Marketer view

Email marketer from Talos Intelligence shares that they provide reputation monitoring services and threat intelligence. They respond that using their tools, you can assess the reputation of your sending IPs and domains and identify potential issues that may affect deliverability.

July 2021 - Talos Intelligence

What the experts say
9Expert opinions

Experts emphasize the importance of monitoring email blacklists for deliverability. Spamhaus is identified as a crucial blacklist, with its different lists (SBL, XBL, PBL) requiring understanding. Monitoring sender reputation is key, with tools like Google Postmaster Tools and Microsoft SNDS recommended. When evaluating blacklists, consider if they block mail, influence delivery decisions, correlate with poor delivery or sender practices. Understanding and following the specific removal process for each blacklist is critical for delisting. Some lists, like Unsubscore, are less respected. Focus should be on relevant blacklists rather than those with minimal impact. It's also important to note that some hostnames, like those for Invaluement, may be outdated.

Key opinions

  • Spamhaus Importance: Spamhaus is consistently highlighted as the most important blacklist to monitor due to its widespread use and impact on deliverability.
  • Sender Reputation: Actively monitoring sender reputation is crucial, enabling timely intervention to prevent long-term negative impacts on deliverability.
  • Removal Processes: Understanding and adhering to the specific removal processes for each blacklist is essential for successful delisting.
  • Blacklist Evaluation: Evaluate blacklists based on their actual impact on blocking mail, influencing delivery decisions, and correlating with poor sender practices.

Key considerations

  • Relevance of Blacklists: Prioritize monitoring efforts on blacklists that significantly impact deliverability, avoiding unnecessary focus on less influential lists.
  • Monitoring Tools: Use appropriate tools, such as Google Postmaster Tools and Microsoft SNDS, to actively monitor sender reputation and identify potential issues.
  • Outdated Information: Be aware that some information regarding blacklist hostnames or processes may be outdated, requiring verification and updates.
  • Proactive Approach: Take a proactive approach to blacklist monitoring and sender reputation management to maintain optimal email deliverability.
Expert view

Expert from Spam Resource explains the importance of understanding the removal process for each blacklist. They share that each blocklist has its own procedures, and following them carefully is key to getting delisted. Ignoring their specific instructions can prolong the listing.

December 2022 - Spam Resource
Expert view

Expert from Email Geeks shares that they don’t have much respect for lashback’s processes, so they wouldn’t care about unsubscore much.

November 2024 - Email Geeks

What the documentation says
5Technical articles

Various documentation sources highlight important email blacklists and methods for checking them. Spamhaus maintains the SBL, ZEN, and DBL, which can be checked via their Blocklist Removal Center (BRC) or direct DNS queries. Barracuda Central's BRBL can be checked through their website's lookup tool. While Proofpoint's DRF cannot be directly checked, maintaining good sending practices is crucial to avoid being flagged. Tools like MultiRBL and MXToolbox offer means to check IPs and domains against multiple blacklists simultaneously, providing an overview of potential listing issues.

Key findings

  • Key Blacklists: Spamhaus (SBL, ZEN, DBL) and Barracuda BRBL are significant blacklists to monitor.
  • Checking Methods: Blacklists can be checked using dedicated lookup tools (Spamhaus BRC, Barracuda Central) or multi-RBL checkers (MultiRBL, MXToolbox).
  • Indirect Assessment: Some reputation filters (Proofpoint DRF) cannot be directly checked, but good sending practices are critical to avoid being flagged.
  • Comprehensive Overview: MultiRBL and MXToolbox allow for simultaneous checks against multiple blacklists for an overview.

Key considerations

  • Direct vs. Indirect Checks: Understand whether a blacklist offers a direct lookup tool or if avoiding listing relies on adhering to best practices.
  • Source Reliability: Consider the reputation and reliability of the blacklist and the checking tool being used.
  • False Positives: Be prepared to address potential false positives by following the delisting procedures for each blacklist.
  • Proactive Approach: Implement proactive measures to maintain good sending reputation to avoid blacklisting in the first place.
Technical article

Documentation from MXToolbox explains that they provide various tools to check email server health, including a blacklist check. They respond that users can use their blacklist checker tool to see if an IP address or domain is listed on multiple popular blacklists.

June 2024 - MXToolbox
Technical article

Documentation from Barracuda Central explains that the BRBL is a real-time database of IP addresses with poor reputation. They respond that you can check if an IP is listed using their lookup tool on the Barracuda Central website. They also offer a removal request process if you believe your IP was listed in error.

December 2022 - Barracuda Central