Should email senders care about RFC-Clueless blocklist listings?

10 Marketer opinions 5 Expert opinions 4 Technical articles 2 Resources

Summary

The overwhelming consensus from experts, marketers, and documentation is that email senders should not be overly concerned about RFC-Clueless blocklist listings. It is generally considered irrelevant due to its limited use by major ISPs, its tendency to list entire TLDs (leading to false positives), and its overall poor reputation. The emphasis should instead be on maintaining a good sender reputation, following email sending best practices, and focusing on reputable blocklists that are actively used by major email providers, such as Spamhaus. Correlation between being on any blocklist and experiencing delivery issues does not necessarily imply causation, as both can stem from underlying sending behavior. Major email providers like Gmail rely more on their own internal technologies than external lists.

Key findings

RFC-Clueless: Irrelevant: RFC-Clueless is widely regarded as an irrelevant blocklist with little to no impact on email deliverability for most senders.
Limited Use by ISPs: Major Internet Service Providers (ISPs) and email providers do not typically use RFC-Clueless for filtering emails.
False Positives: RFC-Clueless lists entire Top-Level Domains (TLDs), leading to a high risk of false positives if used for email blocking.
Focus on Reputable Blocklists: Email senders should prioritize monitoring and avoiding listings on reputable and widely-used blocklists like Spamhaus.
Sender Reputation is Key: Maintaining a good sender reputation through responsible sending practices is more important than worrying about RFC-Clueless.
Correlation, Not Causation: If experiencing delivery issues and listed on a blocklist, it's crucial to investigate underlying sending practices, as correlation does not equal causation.
Internal Filtering Systems: Major email providers, like Google, rely heavily on their own internal spam filtering technologies, making external blocklists less influential.

Key considerations

Sending Best Practices: Adhere to established best practices for email sending, including authentication, relevant content, and respecting recipient preferences.
Reputation Monitoring: Regularly monitor your sender reputation and presence on reputable blocklists to proactively identify and address potential deliverability issues.
Investigate Deliverability Issues: When facing deliverability challenges, investigate the root cause of the issues, focusing on sending practices and content, rather than solely blaming blocklist listings.
Email Authentication: Ensure proper email authentication (SPF, DKIM, DMARC) to improve sender reputation and reduce the likelihood of deliverability problems.

What email marketers say
10Marketer opinions

The consensus from various email marketing experts and community discussions is that RFC-Clueless is not a significant blocklist for email senders. It's generally considered irrelevant as it's not widely used by major ISPs or email providers, and listing entire TLDs can lead to false positives. Focusing on reputable blocklists and maintaining good sending practices is more important for email deliverability.

Key opinions

Irrelevant Blocklist: RFC-Clueless is generally considered an irrelevant blacklist that doesn't significantly impact email deliverability.
Not Widely Used: Major ISPs and email providers do not typically use RFC-Clueless for filtering emails.
False Positives: The list includes entire TLDs, leading to many false positives if used for blocking.
Focus on Reputable Lists: Email senders should prioritize monitoring and avoiding listing on reputable blocklists like Spamhaus.

Key considerations

Sending Reputation: Maintain a good sending reputation by following best practices to avoid being listed on more influential blocklists.
Good Sending Practices: Implement good sending practices to improve email deliverability and avoid deliverability issues in the first place.
Monitor Key Blocklists: Instead of worrying about RFC-Clueless, monitor your presence on widely-used and influential blocklists.

Marketer view

Email marketer from EmailDeliverability.com shares that RFC-Clueless is not one of the blocklists that are checked by most large mail providers so it is unlikely to impact your email deliverability. It only affects sysadmins that use this list.

May 2023 - EmailDeliverability.com

Marketer view

Email marketer from StackExchange shares that you can't get off the RFC-Clueless list and that it is pretty useless and you will probably do more harm than good by trying to filter based on it.

November 2023 - StackExchange

Marketer view

Email marketer from Email Marketing Forum responds that RFC-Clueless is not a reputable or widely used blacklist, and being listed on it is unlikely to affect email delivery to major ISPs. It is generally safe to ignore it.

March 2022 - Email Marketing Forum

Marketer view

Email marketer from Email Geeks believes it has a very specific purpose that most senders wouldn't have to pay much attention to and that RFC-Clueless list entire TLDs, so anyone using this to block emails would generate plenty of false positives.

March 2021 - Email Geeks

Marketer view

Email marketer from Reddit shares that RFC-Clueless is generally considered an irrelevant blacklist for email senders. It doesn't significantly impact email deliverability or reputation.

December 2024 - Reddit

Marketer view

Marketer from Email Geeks believes it has a very specific purpose that most senders wouldn't have to pay much attention to and that RFC-Clueless list entire TLDs, so anyone using this to block emails would generate plenty of false positives.

January 2022 - Email Geeks

Marketer view

Marketer from Email Geeks says that being listed on RFC-Clueless means nothing and will not influence deliverability.

January 2022 - Email Geeks

Marketer view

Email marketer from Mailjet explains that you should monitor your sending reputation and ensure you are not on the important blocklists. They don't comment on RFC-Clueless, but you should focus on the important blocklists.

July 2021 - Mailjet

Marketer view

Email marketer from Email Geeks says that being listed on RFC-Clueless means nothing and will not influence deliverability.

September 2023 - Email Geeks

Marketer view

Email marketer from Quora says that RFC-Clueless is a blocklist that is not used by major mailbox providers. Therefore, it is unlikely to impact your email deliverability. Focus on the major blocklists, such as Spamhaus.

August 2022 - Quora

What the experts say
5Expert opinions

Experts generally agree that RFC-Clueless is not a significant concern for email senders. It is often characterized as a 'grudge list' with limited relevance to actual deliverability issues. The focus should instead be on reputable blocklists like Spamhaus and maintaining good sending practices. While being on any blocklist might correlate with delivery problems, it doesn't necessarily cause them, as detection methods often overlap. It's also noted that major providers like Gmail rely on internal technology more than external blocklists.

Key opinions

RFC-Clueless Irrelevance: RFC-Clueless is considered a low-priority blocklist with limited impact on email deliverability.
Focus on Reputable Lists: Email senders should prioritize monitoring and avoiding listing on reputable blocklists that are actively used by major ISPs.
Correlation vs. Causation: Being on a blocklist and experiencing delivery issues may be correlated but not causally linked; often, both stem from underlying sending behavior.
Internal Technology: Major email providers like Gmail rely heavily on their own internal spam detection technologies rather than solely depending on external blocklists.

Key considerations

Sending Practices: Prioritize maintaining good sending practices to avoid being listed on any blocklist, regardless of its perceived influence.
Reputation Monitoring: Monitor your sending reputation and presence on reputable blocklists to proactively address potential deliverability issues.
Root Cause Analysis: If experiencing delivery problems, investigate the underlying sending practices and content issues rather than immediately assuming a blocklist is the sole cause.

Expert view

Expert from Email Geeks responds that if you're looking for where you’re listed because you’ve seen a delivery issue, it’s extremely unlikely that the listing caused the issue.

November 2023 - Email Geeks

Expert view

Expert from Word to the Wise explains that there are many blocklists, but only a few have significant impact on delivery. While they don't specifically address RFC-Clueless, the advice is to focus on reputable lists and good sending practices.

April 2023 - Word to the Wise

Expert view

Expert from Email Geeks explains that RFC-Clueless is a grudge list run by someone with a limited reading of an informational RFC. More broadly, just because a provider says your IP/domain is on a list isn’t necessarily a reason to care. Only a few lists provide useful information or affect delivery. Blocklists have reputations, and ISPs use high-reputation ones like Spamhaus. Being on a list and being blocked often happen together, but correlation isn't causation; detection methods overlap.

June 2022 - Email Geeks

Expert view

Expert from Email Geeks answers question on if Gmail uses outside lists, Google relies more on their own internal technology. Spam detection methods overlap and being listed on any list may correlate with delivery problems because the two systems are seeing the same behaviour, not because one is consuming data from the other.

July 2024 - Email Geeks

Expert view

June 2022 - Email Geeks

What the documentation says
4Technical articles

Documentation sources suggest that RFC-Clueless is not a significant concern for email senders. RFC-Clueless.org describes its purpose as a tool for sysadmins to block RFC-ignorant hosts. DNSQueries indicates the list has a poor reputation due to listing entire TLDs and recommends against taking it seriously. More broadly, both TalosIntelligence and Google Workspace emphasize the importance of maintaining a good sender reputation and following best practices for email deliverability, implying that a focus on these aspects makes worrying about less influential blocklists unnecessary.

Key findings

Limited Influence: RFC-Clueless is intended for specific sysadmin use and is not widely adopted or influential in deliverability.
Poor Reputation: RFC-Clueless has a negative reputation due to its practice of listing entire Top-Level Domains (TLDs).
Sender Reputation Matters: Maintaining a good sender reputation and following best practices for email deliverability are key and make worrying about less influential blocklists like RFC-Clueless unnecessary.

Key considerations

Good Sending Practices: Prioritize following established best practices for email sending (authentication, content, frequency, etc.).
Sender Reputation: Focus on maintaining a positive sender reputation through consistent and responsible email practices.
Authenticating Email: Properly authenticate your email to improve sender reputation and reduce deliverability issues.

Technical article

Documentation from Google Workspace shares that you should authenticate your email, only send wanted emails and monitor your sending reputation. They don't comment on RFC-Clueless but focusing on your sending reputation will improve your deliverability.

February 2023 - Google Workspace

Technical article

Documentation from RFC-Clueless.org explains that the list is for sysadmins who wish to block email from hosts violating standards and that adhere to rfc-ignorant practices.

June 2022 - RFC-Clueless.org

Technical article

Documentation from TalosIntelligence explains that maintaining a good sender reputation is key to email deliverability. While they don't directly comment on RFC-Clueless, the best practice is to focus on improving your sending reputation and practices so you don't have to worry about 3rd party blocklists.

March 2022 - TalosIntelligence.com

Technical article

Documentation from DNSQueries explains that RFC-Clueless is a blocklist that has a bad reputation because it lists entire TLDs. You cannot request delisting and this list is not to be taken seriously.

February 2024 - DNSQueries