Why is my domain listed in Razor2 and how do I remove it?

The common misconception is that a domain itself is directly listed, similar to how an IP address might appear on an RBL. However, Razor2 assigns a score to email content based on fuzzy checksums. A high Razor2 score indicates that the email's content (or parts of it) closely resembles known spam patterns, leading to messages being filtered or blocked. This can occur even if the domain hasn't been used for bulk emailing recently, but historically sent content that was reported, or if current low-volume sending includes problematic content. Understanding this distinction is key to addressing the issue and improving your overall email deliverability.

Key findings

• Content-based system: Razor2 primarily focuses on the message body, using fuzzy checksums to identify content that looks like previously flagged spam.
• Not an RBL: Unlike traditional real-time blackhole lists (RBLs), Razor2 does not blacklist (or blocklist) IP addresses or domains directly.
• SpamAssassin integration: Razor2 is commonly used in conjunction with SpamAssassin, a popular open-source spam filtering platform.
• Delisting difficulty: There's no direct delisting process for Razor2 as it's a distributed network. The solution lies in addressing the content and sending practices.
• Historical sending matters: Even if a domain isn't actively sending bulk emails, past problematic content or a compromise leading to spam could still cause Razor2 hits.

Key considerations

• Content review: Thoroughly examine the content of your emails, even those sent in low volumes, to ensure they don't contain elements common in spam.
• DMARC reports: Leverage DMARC reports to identify all sources sending email on behalf of your domain. Unexpected sending sources can reveal compromises or forgotten applications.
• Sender reputation: A poor overall domain reputation (independent of Razor2) can exacerbate content-related filtering. Focus on best practices to improve sender reputation.
• Ongoing monitoring: Continuously monitor your sending practices and email content to prevent recurrence of issues. Regular blacklist checks (for IP/domain blacklists) and DMARC monitoring are good practices.

The consensus among marketers is to meticulously review current and past sending activities, with DMARC reports frequently cited as an invaluable tool for uncovering hidden sending sources. While direct delisting from Razor2 isn't feasible, addressing the content and stopping unauthorized sending are the primary steps to improving inbox placement.

Key opinions

• DMARC is crucial: Many marketers emphasize using DMARC reports to detect unexpected email sending from their domains, which can be the root cause of Razor2 hits.
• Content is king: The primary driver for Razor2 flags is the email's content, not necessarily the domain's reputation or IP itself. Marketers need to scrutinize their message bodies.
• Historical baggage: Even domains perceived as inactive might have historical sending issues or compromised systems that lead to current Razor2 listings.
• Indirect impact on domain: While Razor2 doesn't blacklist domains directly, consistent Razor2 hits on content from a domain can negatively affect its overall domain reputation.

Key considerations

• Verify sending sources: Always cross-reference DMARC data with your known sending platforms to account for all email traffic originating from your domain.
• Content remediation: If specific content triggers Razor2, modify or cease sending that content. This is the most direct way to stop Razor2 hits.
• Spam report analysis: For issues detected by SpamAssassin, carefully read the spam report to understand which rules, including Razor2, are being triggered. This analysis can guide content adjustments.
• Audit legacy systems: Regularly audit any old applications or servers that might still be configured to send email, even if they're thought to be inactive.

They consistently point to the importance of DMARC reporting for identifying all sending sources (including hidden ones) and advocate for a proactive approach to content quality. Recovering from Razor2 issues is about adapting sending practices and content, rather than requesting removal from a list that doesn't exist in the traditional sense.

Key opinions

• Content, not RBL: Experts firmly state that Razor2 is a distributed fuzzy checksum-based filter that operates on the message body, distinguishing it from RBLs (blocklists).
• No direct domain link: Sending domain reputation is separate from Razor2 checks, which are purely about content. While a poor domain reputation might exist, Razor2's focus remains on checksumming the message body.
• Practical delisting impossible: Due to its distributed nature, directly 'delisting' from Razor2 is not practically feasible, as it would require many clients to vote the content as non-spam.
• Solution is content change:The only effective solution is to stop using the problematic content and address the sending practices that cause the spam classification.
• DMARC for source identification: DMARC reports are highlighted as a means to discover where email, potentially with flagged content, is originating from within one's infrastructure.

Key considerations

• Analyze email content: Focus forensic efforts on the specific content that is triggering Razor2 hits, as this is the direct cause.
• Identify sending origins: Even if you think a domain is inactive, a Razor2 hit implies recent sending. Use tools like DMARC monitoring to find all sources.
• Reputation correlation: While Razor2 is content-based, a poor overall domain reputation (as seen by other filters) can correlate and compound deliverability issues.
• Long-term strategy: Since direct delisting isn't possible, focus on a long-term strategy of sending clean, desired content and maintaining good sending hygiene to naturally avoid Razor2 triggers.

The documentation underscores that Razor2 issues are typically resolved by modifying the email content or stopping the sending of problematic messages, rather than by requesting a domain or IP delisting. Understanding this technical distinction is fundamental to effective remediation.

Key findings

• Checksum-based: Razor2 employs distributed fuzzy checksums on email content to detect spam. This allows for detection of variations of known spam messages.
• Collaborative network: It's part of a decentralized network where users report spam, contributing to the shared database of content signatures.
• SpamAssassin component: Razor2 is a plugin for SpamAssassin, where it contributes to the overall spam score of an email. A high Razor2 score indicates a strong content match to known spam.
• No direct delisting API: There isn't a direct API or public interface for individual delisting requests from the Razor2 network itself, as it relies on collective reporting.

Key considerations

• Content modification: To resolve Razor2 issues, the primary action is to revise email content to ensure it does not resemble previously flagged spam patterns.
• Identify source of spam content: If the content is legitimate, investigate why it's being flagged. This could involve unintended text, links, or image properties. Ensuring proper email authentication (SPF, DKIM, DMARC) is also fundamental.
• Prevent future hits: Implement robust email hygiene practices to prevent sending content that could be interpreted as spam by Razor2 or other filters. Regularly test your email content to identify potential issues before sending.
• Understand scoring: Familiarize yourself with how SpamAssassin (and thus Razor2) contributes to email scoring. This knowledge allows for more targeted adjustments to your email campaigns.