How to identify and manage domains protected by Cloudmark?

Key findings

• Hidden protection: Cloudmark's filtering systems are often layered or operate via on-site appliances, meaning their presence isn't always revealed by a direct MX record lookup.
• Proofpoint acquisition: Cloudmark was acquired by Proofpoint, which results in a combined filtering approach for many major mailbox providers.
• Proactive identification: Relying on hard bounces as the sole indicator for Cloudmark-protected domains is inefficient. Proactive identification is key to managing deliverability.
• Warming effectiveness: Traditional IP warming may not resolve Cloudmark-related issues, suggesting that underlying sending practices are often the more critical factor.
• Spam complaints: Deliverability problems with Cloudmark often stem from recipients marking emails as spam, regardless of the list acquisition method.

Key considerations

• MX record analysis: While not exhaustive, checking for domains under cloudfilter.net in MX records can provide some initial insights into Cloudmark's presence.
• Sending practices: If issues arise after warming or an ESP migration, re-evaluate consent mechanisms and your list hygiene practices (even for opt-in lists) to improve your email deliverability.
• Remediation requests: Submitting a remediation request to Cloudmark (or Proofpoint) is a necessary step once you identify a blocklisting.
• Throttling: After resolving an issue, implement throttling for specific domains to gradually re-establish trust and maintain good sending reputation.
• Expert consultation: For persistent or complex issues, consider consulting with deliverability experts who can analyze specific sending networks and IP addresses.

Key opinions

• Warming skepticism: Many marketers express doubt about the effectiveness of IP warming alone in resolving Cloudmark-related blocklistings.
• Hidden protection: Marketers find it challenging to identify Cloudmark protection solely through MX records, as Cloudmark can operate behind other services.
• Post-migration issues: Cloudmark issues sometimes emerge after an ESP migration, even following extensive list validation.
• Practices over warming: There is a strong belief that poor sending practices (e.g., list acquisition, content relevance) are more likely causes than insufficient warming.
• Hard bounces: Emails impacted by Cloudmark are often categorized as hard bounces, complicating their management and remediation.

Key considerations

• Proactive suppression: Marketers seek methods to suppress emails to Cloudmark-protected domains before sending, thereby helping to avoid blocklistings.
• Consent validation: Even with explicit opt-in, marketers should continuously review their consent processes, especially for lead generation campaigns.
• Content consistency: Avoid unexpected content changes for existing contact bases to maintain engagement and minimize complaints.
• List hygiene: Ongoing email validation remains critical to remove invalid or problematic addresses.
• Throttling strategy: After a Cloudmark blocklist is resolved, a cautious throttling strategy to impacted domains can aid in re-establishing deliverability.

Key opinions

• Warming's limited use: Experts generally concur that IP warming is not the main solution for Cloudmark-related deliverability problems.
• Practices over warming: The root cause of Cloudmark issues often lies in poor sending practices, such as how the email list was acquired or managed.
• Hidden deployments: Cloudmark can operate behind other MX records or through on-site appliances, making direct identification challenging.
• Proofpoint integration: Cloudmark's acquisition by Proofpoint implies that filtering might be a combined effort, and pinpointing specific Cloudmark involvement can be tricky.
• Direct analysis needed: For complex or persistent cases, experts advise providing specific network and IP details for accurate problem diagnosis.

Key considerations

• MX record limitations: Do not solely depend on MX records to identify Cloudmark-protected domains due to their deep integration and layered approach.
• Consent rigor: Implement robust, explicit consent mechanisms for all list building to prevent future spam complaints, which are often the true cause of blocklistings.
• Complaint analysis: Investigate any unexpected increases in spam complaints, as this frequently indicates an underlying issue with list quality or content relevance.
• Holistic review: Conduct a comprehensive review of your sending practices, including list sourcing, engagement strategies, and content relevance, to identify areas for improvement. This helps manage and identify the cause during an email blacklisting and understanding why your IP is listed on Cloudmark CSI-Global.
• Professional consultation: When facing persistent Cloudmark issues, seeking direct consultation with deliverability specialists can provide targeted insights, as outlined in this article on self-help deliverability checks.

Key findings

• Global reach: Cloudmark is a significant anti-spam provider, responsible for protecting billions of mailboxes worldwide.
• Acquisition by Proofpoint: Cloudmark was acquired by Proofpoint, leading to the integration of its threat intelligence capabilities into Proofpoint's broader security offerings.
• Real-time threat intelligence: Cloudmark Insight tracks real-time threat intelligence information across various data points, including IP addresses, domains, URLs, and textual content.
• Optimized delivery: Cloudmark's services are engineered to manage email transmission and reception efficiently, optimizing network-wide delivery at exceptional speeds.
• Malicious domain intelligence: Its threat intelligence specifically includes data on malicious domains, which complements email fraud defense and domain defense products.

Key considerations

• Unified defense: Understand that Cloudmark's capabilities are now often part of a broader Proofpoint security suite, which affects how deliverability issues are addressed.
• Data tracking: Be aware that Cloudmark tracks various data points (IPs, domains, URLs, content) to build its comprehensive threat intelligence. This information is key to understanding which major Mailbox Providers use Cloudmark.
• Proactive security: Leverage Cloudmark's real-time threat intelligence for proactive defense against spam and phishing attacks.
• System integration: Recognize that Cloudmark may be deeply integrated within communication service providers, not just as a standalone MX, which is important when trying to identify email filtering security measures.
• Deliverability impact: Appreciate that Cloudmark's sophisticated filtering capabilities can significantly impact email deliverability based on its assessment of perceived threat levels.