Summary
Assessing unknown email blacklists, such as NoSolicitado, requires a strategic approach focused on their actual impact rather than simply their existence. Many lesser-known blacklists, including NoSolicitado, are often found to have minimal influence on overall deliverability, especially to major Internet Service Providers (ISPs). NoSolicitado specifically is noted as a private, low-impact list primarily prevalent in Latin America, often regarded as unreliable or even a 'scam' by some experts, with delisting processes that may appear suspicious or demand payment. The consensus is that resources are better spent on maintaining good sending hygiene and focusing on major, reputable RBLs rather than expending effort on inconsequential or illegitimate lists.
Key findings
- NoSolicitado's Limited Impact: NoSolicitado is a low-impact, private blacklist primarily prevalent in Latin America (especially Chile and Central America), and is often regarded as a 'scam' or 'fake' list with minimal influence on deliverability to major ISPs.
- Prevalence of Irrelevant Lists: There are numerous entirely irrelevant blacklists, some of which are included in 'check multiple blacklists' tools but have little to no actual effect on mainstream email deliverability.
- Suspicious Delisting Practices: Blacklists like NoSolicitado may have suspicious delisting processes, including requests for payment, which is a strong indicator of their low reputation and negligible impact.
Key considerations
- Verify Blacklist Type & Reputation: Determine the blacklist's type (e.g., DNSBL, internal list) and assess its reputation by checking how many major ISPs or recipient domains actively reference or utilize it.
- Examine Delisting Policy & Transparency: Look for a clear, transparent delisting policy. If the list lacks transparency, has obscure processes, or charges fees for delisting, it is likely of low impact or illegitimate, and should generally be disregarded.
- Understand Methodology & Adoption: Investigate the blacklist's methodology-how entries are added-and, critically, its adoption rate among your target recipients' email providers to gauge its actual impact on mail flow.
- Prioritize Major RBLs & Sender Hygiene: Focus efforts on maintaining good sender reputation and compliance with the guidelines of major email providers, as well as preventing listings on widely used and reputable RBLs (e.g., Spamhaus, Barracuda, SpamCop), rather than expending resources on obscure or inconsequential lists.
What email marketers say
13 marketer opinions
Interpreting and assessing unfamiliar email blacklists requires discerning their true influence on email deliverability. Many such lists, including the frequently cited NoSolicitado, are often found to have very limited impact, particularly on mail sent to major Internet Service Providers. NoSolicitado specifically is identified as a small, regionally prevalent list, mainly in Latin America, which some experts regard as having little practical consequence, or even being a 'scam,' due to its low adoption and questionable delisting methods that may involve payment. The general consensus from deliverability experts is that an email sender's focus should remain on upholding a strong sender reputation and complying with the guidelines of major email providers and widely recognized public blacklists, rather than expending effort on these obscure or illegitimate lists.
Key opinions
- NoSolicitado Characteristics: NoSolicitado is a low-impact blacklist, primarily affecting recipients in Latin America, and is often considered unreliable or a 'scam' due to its minimal influence on major ISPs and suspicious delisting practices.
- Prevalence of Obscure Lists: Many blacklists are entirely irrelevant to overall deliverability, despite being included in tools that check multiple lists, and they hold little to no sway with mainstream email providers.
- Indicators of Low Credibility: Blacklists lacking a public query tool, transparent delisting processes, or those requesting payment for removal are typically private, less reputable, and have negligible impact on deliverability to major email providers.
Key considerations
- Evaluate Blacklist Legitimacy: Assess the blacklist's legitimacy by examining its public reputation, whether it offers a clear query tool, and if it's widely referenced by major email providers.
- Scrutinize Delisting Procedures: Carefully review the delisting process; any demands for payment or a lack of transparency are strong indicators that the blacklist is not widely impactful and can often be disregarded.
- Prioritize Major RBLs: Direct resources towards preventing listings on well-known, impactful RBLs like Spamhaus, Barracuda, and SpamCop, and focus on maintaining excellent sender reputation, as these efforts yield far greater deliverability benefits than chasing obscure lists.
Marketer view
Email marketer from Email Geeks explains that Litmus should have support content for the RBLs they test, advises not to worry about insignificant lists, and identifies main public RBLs to watch including Spamhaus, Barracuda, SpamCop, ReturnPath, SORBS, and Cloudmark. He further clarifies that many niche, regionally focused, or garage operated RBLs exist, and their usefulness to an organization depends on understanding their listing criteria and potential usage.
18 May 2025 - Email Geeks
Marketer view
Email marketer from Email Geeks explains that NoSolicitado has low impact and is basically prevalent in LATAM.
25 Jul 2021 - Email Geeks
What the experts say
2 expert opinions
Understanding the true impact of an unfamiliar email blacklist, such as NoSolicitado, is crucial for effective deliverability management. Experts note that NoSolicitado is a private list with very limited adoption by major Internet Service Providers, primarily affecting a small number of mail services in specific regions. The real significance of any unknown blacklist, therefore, hinges entirely on its widespread use by major ISPs and its actual influence on a sender's target audience. If a list is not widely utilized, its impact on mail flow is negligible, and a listing on such a list, like NoSolicitado, should not be a primary concern.
Key opinions
- NoSolicitado's Specifics: NoSolicitado operates as a private blacklist with minimal adoption among major ISPs, seeing limited use predominantly by certain mail services in specific geographical areas.
- Adoption as Key Indicator: The true relevance of any unknown email blacklist is directly proportional to its active utilization by major Internet Service Providers (ISPs) and a significant portion of the email sender's recipient audience.
Key considerations
- Assess ISP Adoption: Determine if major Internet Service Providers (ISPs) or a substantial segment of your recipient base actively use the unknown blacklist, as this is the primary indicator of its real-world impact.
- Evaluate Regional Influence: Consider if the blacklist, like NoSolicitado, is primarily regional or private, which often suggests a limited influence on global or widespread deliverability.
Expert view
Expert from Word to the Wise explains that NoSolicitado is a private blacklist with limited adoption by major ISPs, primarily used by a few mail services in certain regions, meaning a listing might not have widespread impact.
14 Apr 2024 - Word to the Wise
Expert view
Expert from Word to the Wise shares that to assess an unknown blacklist, email senders should determine if major Internet Service Providers (ISPs) or a significant portion of their recipient base actively utilize the list, as its importance is directly tied to its adoption and impact on mail flow.
14 Mar 2023 - Word to the Wise
What the documentation says
5 technical articles
Understanding how to assess an unknown email blacklist, such as NoSolicitado, involves determining its actual influence on deliverability. Experts advise evaluating if the list is widely adopted by major Internet Service Providers (ISPs), examining its operational transparency, and checking for clear delisting policies. Lists that are obscure, charge fees for removal, or are not referenced by prominent email providers like Google or Microsoft typically have minimal effect on overall email deliverability, highlighting the importance of focusing on core sender reputation and widely recognized RBLs.
Key findings
- Relevance by Adoption: The actual impact of an unknown blacklist is directly tied to its adoption and reference by major ISPs and prominent email providers. If not widely used, its effect on deliverability is minimal.
- Indicators of Low Influence: Blacklists lacking clear governance, transparent delisting policies, or those that charge for removal are generally considered low-impact or illegitimate, and do not significantly affect mail flow to major recipients.
- Shift to Sender Reputation: Major email services prioritize sender reputation, content quality, and user feedback over obscure blacklists, underscoring that efforts are better spent on these fundamental deliverability factors.
Key considerations
- Assess ISP Integration: Determine whether major Internet Service Providers actively consult or incorporate the unknown blacklist into their spam filtering mechanisms.
- Evaluate Transparency and Fees: Investigate the blacklist's operational transparency and delisting policies; the presence of fees or a lack of clear procedures signals low credibility.
- Prioritize Established Deliverability Practices: Concentrate resources on maintaining strong sender reputation and adhering to best practices that prevent listings on reputable, widely used blacklists rather than obscure ones.
Technical article
Documentation from Mailgun explains that when assessing an unknown blacklist, it's crucial to verify its type (e.g., DNSBL, internal list), check its reputation by determining how many major ISPs reference it, and look for a clear delisting policy. If the list lacks transparency or charges fees for delisting, it's likely of low impact or illegitimate.
30 Apr 2024 - Mailgun
Technical article
Documentation from M3AAWG advises that assessing lesser-known blacklists involves understanding their methodology (how entries are added), their adoption by recipient domains (to gauge actual impact), and the availability of a transparent delisting process. If a blacklist is not widely adopted by major ISPs or lacks clear governance, its effect on deliverability is considered minimal.
22 Jan 2022 - M3AAWG (Messaging, Malware and Mobile Anti-Abuse Working Group)
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