Summary
The question of whether to block the .us top-level domain (TLD) for email signups is nuanced. While some marketers consider it a potential source of problematic signups, especially in industries prone to abuse like dating sites, experts generally advise against blanket TLD blocks due to the risk of legitimate user exclusion. The .us TLD, managed by Neustar, is noted for its good abuse management, suggesting it may not be as problematic as other less common domain extensions. Effective signup protection often involves a combination of strategies, including robust email validation services and behavioral analysis, rather than solely relying on TLD blacklists.
Key findings
- Legitimate Use: There are many legitimate organizations and individuals using the .us TLD, including vendors and businesses.
- Operator Reputation: The .us TLD is operated by Neustar, which has a strong reputation for managing abuse and registrations effectively.
- Targeted Blocking: Blocking entire TLDs is generally considered a blunt instrument. While it can reduce certain types of unwanted signups, it risks excluding legitimate users.
- Industry Specificity: The decision to block a TLD might be more appealing in specific, high-risk industries like adult dating sites, where the tolerance for fraudulent signups is lower.
Key considerations
- False Positives: A blanket block on .us could lead to significant false positives, preventing genuine users from signing up.
- Abuse Management: Consider the abuse and registration management policies of the TLD operator. TLDs like .us, with robust management, may not warrant a blanket block.
- Alternative Solutions: Instead of TLD blocking, focus on advanced email validation, behavioral analysis, honeypots, or CAPTCHA to combat fraudulent signups. This provides a more targeted approach to blocking unwanted user registrations.
- Specific Problem TLDs: While .us may not be a primary target, certain TLDs (.xyz, .info, .online, etc.) are more frequently associated with spam and could be considered for stricter filtering. You can find data on this from organizations like Spamhaus.
What email marketers say
Email marketers often grapple with high volumes of fraudulent signups and spam, leading them to consider aggressive filtering techniques like blocking entire top-level domains (TLDs). The appeal of such a broad stroke is the potential to quickly reduce unwanted traffic. However, this approach introduces the risk of alienating legitimate users, a crucial concern for any business relying on user acquisition. Balancing strict security with user accessibility remains a key challenge for marketers trying to prevent fake registrations while maintaining deliverability.
Key opinions
- Spam from new TLDs: Many marketers report receiving significant amounts of spam from newer or less common TLDs, leading them to consider blocking these domains.
- Effectiveness for specific use cases: For platforms like dating sites, blocking TLDs (or specific domains) can be a pragmatic approach to immediately mitigate bad signups.
- Legitimacy concerns for .us: Some marketers are unsure about the legitimacy of .us domains, questioning if there are many genuine sites using this TLD.
- Internal system configuration: Marketers often have the capability within their internal systems to configure and apply TLD-based blocklists for signups.
Key considerations
- Avoiding over-blocking: While some TLDs might be heavily abused, a blanket block on widely used TLDs like .us can prevent legitimate users from registering.
- Dynamic threat landscape: Spammers and bots constantly adapt, meaning TLD blocklists may need frequent updates and might not offer a long-term solution for preventing bot sign-ups.
- Balance with user experience: Marketers must weigh the security benefits of TLD blocking against the potential negative impact on the user experience and legitimate signups. According to Zendesk support, administrators commonly use allowlists and blocklists, requiring careful management.
- Leverage advanced tools: Utilize more sophisticated email validation and fraud detection services that analyze multiple factors beyond just the TLD.
Marketer from Email Geeks asks if blocking entire TLDs is a common practice. They personally can't recall seeing many legitimate sites using the .us TLD, which leads them to question its general legitimacy for email signups.
Marketer from Spiceworks Community reports experiencing a significant volume of spam daily from newer top-level domains such as .faith, .website, .win, .racing, .review, and .date. This consistent influx suggests that blocking these specific TLDs could be a viable strategy for reducing spam.
What the experts say
Experts in email deliverability and anti-abuse generally advocate for a cautious approach when considering blanket TLD blocks. While they acknowledge that certain TLDs are indeed associated with higher rates of abuse, they emphasize the importance of distinguishing between email delivery (where TLD blocking can cause significant deliverability issues) and signup filtering. For signups, the approach might be squishier, but still ideally relies on more sophisticated methods than simple TLD lists. They often highlight the reputable management of TLDs like .us and suggest focusing on identifying spam traps and patterns of abuse rather than broad blocklists.
Key opinions
- Legitimate .us use: Many legitimate users and businesses, including vendors, utilize the .us TLD.
- Operator credibility: Neustar, the operator of .us, is highly regarded for its robust abuse management and registration policies, suggesting a low likelihood of widespread abuse originating from this TLD.
- Manual list limitations: Relying on manually maintained blocklists, especially those based on easily faked message bits, is generally inefficient and prone to errors for email delivery.
- Signup blocking distinction: Blocking TLDs for signups is a different scenario from blocking for email delivery, though it still requires careful consideration due to its impact on user acquisition.
Key considerations
- Blunt instrument: Blocking entire TLDs is a blunt instrument that, while potentially reducing some spam, carries a high risk of blocking legitimate users and should be an exception rather than a rule, as noted by experts on Spamresource.com.
- Focus on abuse patterns: Instead of TLDs, focus on identifying specific patterns of abuse or compromised accounts, which offers a more precise approach to security.
- Reference reputation lists: Consult established lists (like Spamhaus TLD statistics) for TLDs with historically high abuse rates if you must implement TLD-based blocking.
- Holistic fraud prevention: Integrate a comprehensive fraud prevention strategy that includes real-time validation, behavioral analysis, and IP reputation, rather than relying solely on domain extensions. This aligns with advice to prioritize robust email list validation strategies.
Expert from Email Geeks asserts that there are numerous legitimate users of the .us TLD. This statement directly challenges the notion that the .us domain is primarily associated with illegitimate activities, suggesting caution against blanket blocking policies.
Expert from Wordtothewise states that while some TLDs, particularly newer ones, do indeed exhibit a higher proportion of abuse, implementing a blanket block is seldom the most effective approach for ensuring long-term email deliverability. They advise against overly broad restrictions that could impact legitimate communications.
What the documentation says
Official documentation and research often provide a more structured and data-driven perspective on TLD management and blocking. They highlight the technical mechanisms for filtering, the importance of authoritative data on TLD abuse rates, and the broader context of anti-spam and fraud prevention. While some documentation details how to configure TLD blocks, it often implicitly or explicitly advises against indiscriminate application, favoring targeted approaches informed by statistical evidence. Resources like Spamhaus TLD statistics are valuable for making informed decisions based on known abuse patterns across different TLDs.
Key findings
- Data-driven approach: Authoritative sources, like Spamhaus, compile statistics on TLD abuse rates, providing crucial data for evaluating which TLDs might genuinely warrant closer scrutiny or blocking.
- Technical implementation: Documentation for systems like Microsoft 365 or Auth0 outlines the technical steps to configure TLD blocks or deny user signups based on email domains.
- Preventing unwanted emails: Some documentation suggests that blocking certain TLDs can be a method to prevent receiving unwanted emails into an organization's systems.
- Pre-registration actions: Platforms often support pre-user registration actions to block or prevent signups from specific domains or TLDs, though these may have limitations (e.g., with social connections).
Key considerations
- Granularity: While TLD blocking is possible, documentation often implicitly encourages more granular control, such as blocking specific domains or implementing broader anti-spam measures.
- Official TLD reputation: The operational quality and abuse management of a TLD registrar (like Neustar for .us) should be considered, as well-managed TLDs are less likely to be sources of high abuse. This is a factor discussed in the context of DNSBLs.
- Quarantining vs. blocking: Some documentation suggests quarantining emails from suspicious TLDs rather than outright blocking them, allowing for review and reducing false positives.
- Policy-based management: Organizations can define policies to allow or block email domains based on their specific needs, using features like Microsoft 365's mail flow rules for example, to block top-level domains.
Documentation from ALI TAJRAN advises that for some TLDs, which an organization definitively wishes to avoid receiving emails from, immediate blocking is the recommended course of action. This ensures that such unwanted communications are prevented from entering the organizational system from the outset.
Auth0 Community documentation suggests that typically, a Pre-User Registration Action would be used to block and prevent users from signing up. However, it notes that this particular flow does not apply to social connections, indicating a limitation for certain signup methods.
