Summary
A domain can be listed on Spamhaus DBL even when not actively sending emails due to various factors impacting domain reputation and usage. DBL listings indicate current detection in spam, encompassing direct inclusion in spam content (URLs, websites), passive referencing on spam-sending pages, or usage in HELO domains. Problems can stem from domain abuse (hijacking, malicious URL shortening, SEO poisoning, malware distribution), compromised websites hosting spam, parked domains with malicious content, and past email marketing practices or even historical spam activity. Underlying technical issues can include EHLO forgery and content injection. Addressing this requires security measures such as SPF records and CSP/SRI policies, actively monitoring domain reputation with tools like Google Search Console, checking DNS records for tampering, scanning the domain for malicious URLs, auditing website content and ensuring no unauthorized resources are present, investigating the shared hosting server's IP address reputation, and concurrent resolution of any associated IP listings.
Key findings
- Current Detection: DBL listings indicate the domain is currently detected in spam, regardless of active sending.
- Content Matters: The domain's usage in content, like links or images, is sufficient for listing, even without direct sending.
- Abuse & Compromise: Hijacking, URL shortening abuse, compromised sites, or malicious parked domains lead to listings.
- Historical Impact: Past spam activity, even if infrequent, and poor reputation scores can contribute to a DBL listing.
- Technical Vulnerabilities: EHLO forgery and content injection can contribute to a domain being listed.
Key considerations
- Content Audit: Regularly audit website content, URLs, and hosted files for malicious code or unauthorized presence.
- Reputation Management: Monitor domain reputation with tools and services. Implement feedback loops.
- DNS Security: Review and secure DNS records, and enforce SPF to prevent EHLO forging.
- Technical Hardening: Implement Content Security Policies and Subresource Integrity to mitigate content injection risks.
- Hosting Review: Investigate shared hosting server reputation and consider switching providers if necessary.
- Monitor blocklists: Continuously monitor listing status on Spamhaus and other blocklists and delist appropriately.
What email marketers say
9 marketer opinions
A domain can be listed on the Spamhaus DBL even when not actively sending emails for several reasons. These include past email marketing practices impacting domain reputation, the domain being used for a HELO domain, a compromised website hosting spam content unknowingly, parked domains displaying malicious content, URLs on the domain containing malware, the domain's historical data, the reputation of a shared hosting server's IP address, or the use of URL redirection services associated with spam. Addressing these issues requires investigation into past activities, domain security, hosting environment, and content to ensure compliance with spam prevention practices.
Key opinions
- Past Practices: Previous email marketing campaigns or practices could have negatively impacted the domain's reputation, leading to a DBL listing.
- Compromised Website: The website may be compromised and hosting spam content without the owner's knowledge.
- Domain Parking: If the domain is parked, the parking service may be displaying malicious advertising or content.
- Malicious URLs: URLs on the domain may contain malware or malicious code.
- Shared Hosting: The reputation of the shared hosting server's IP address can affect the domain's listing.
- URL Redirection: Use of URL redirection services associated with spam can result in listing.
- HELO Domain: The domain may have been used for a HELO domain in the past, causing the MTA IP to be listed.
Key considerations
- Review History: Review past email marketing campaigns and practices to identify any potential issues that may have impacted domain reputation.
- Security Audit: Conduct a thorough security audit of the website to ensure it has not been compromised and is not hosting any unauthorized content.
- Hosting Provider: Investigate the reputation of the shared hosting server's IP address and consider switching providers if necessary.
- URL Scanning: Scan URLs on the domain to identify and remove any that contain malware or malicious code.
- Monitor Domain: Monitor domain reputation using tools like Google Search Console and Spamhaus's domain lookup tool.
- Check parked domain content: If parked, check the content and advertising on the domain, as this can lead to issues.
Marketer view
Email marketer from EmailGeeksForum explains a listing can be associated with the domain's historical data and that domain reputation is not built or destroyed overnight; it takes time.
29 Sep 2024 - EmailGeeksForum
Marketer view
Marketer from Email Geeks confirms the domain was used for a HELO domain until April 5th and the MTA IP is also listed by Spamhaus due to the domain.
28 Nov 2024 - Email Geeks
What the experts say
8 expert opinions
A domain can be listed on the Spamhaus DBL even if it's not actively sending emails due to various factors. DBL listings reflect current usage, meaning the domain is likely present in spam content or email, even if passively. This can include links, images, or redirects hosted on the domain, potentially used by bad actors. Addressing this requires checking URLs, ensuring domain security (including SPF records to prevent EHLO forgery), resolving any associated IP listings concurrently, and implementing content security measures to prevent code injection. The usage of the domain in content is sufficient for listing, even if the domain is not actively sending mail itself.
Key opinions
- Active Detection: DBL listings indicate that the domain is currently being detected in spam, even if not directly sending emails.
- Content Usage: The domain's usage in email content (links, images) is enough to trigger a DBL listing, even without direct sending.
- Security Risks: Bad actors can use the domain's resources in their spam emails, leading to a DBL listing.
- Concurrent Listing: IP addresses and the domain can be listed concurrently, requiring simultaneous resolution.
- EHLO Forgery: The domain could be forged in the EHLO, leading to a listing, which can be mitigated with SPF records.
- Content Injection: Code injection can cause the domain to be listed. You can make use of Content Security Policies (CSP) and Subresource Integrity (SRI) to resolve this.
Key considerations
- Content Review: Carefully review URLs and content hosted on the domain to ensure they are not present in any spam campaigns.
- Security Measures: Implement security measures like SPF records to prevent EHLO forgery and unauthorized use of the domain.
- IP Resolution: Address any IP listings associated with the domain concurrently with the DBL listing.
- Monitor Listings: Continuously monitor the domain's listing status on Spamhaus and other blocklists.
- CSP/SRI Configuration: Implement and maintain Content Security Policies (CSP) and Subresource Integrity (SRI) to prevent content injection.
Expert view
Expert from Word to the Wise explains that you should check the URLs used in email campaigns and on your website, as these could be present in spam even if you're not actively sending emails. Even URLs to resources on your domain can be enough for listing.
1 Jun 2023 - Word to the Wise
Expert view
Expert from Email Geeks asks if the domain hosts links or images used in external emails, suggesting a bad actor might be using the domain in their mail.
3 Aug 2022 - Email Geeks
What the documentation says
5 technical articles
A domain can be listed on Spamhaus DBL, even without actively sending emails, due to its presence in spam content. This includes being used in URLs, spamvertised websites, or referenced on spam-sending pages. Other causes encompass domain hijacking, use in URL shortening services associated with spam, SEO poisoning, and malware distribution. Addressing this requires checking for unauthorized content, monitoring domain reputation via tools like Google Search Console, reviewing DNS records for tampering, and understanding that even infrequent past spam activity tracked by networks like Cisco's SenderBase can impact the domain's reputation.
Key findings
- Passive Listing: Domains are listed based on their presence in spam, regardless of active email sending.
- Content Association: Inclusion in URLs or content on spam-sending pages can trigger listing.
- Domain Abuse: Hijacking, malicious URL shortening, SEO poisoning, and malware distribution contribute to listings.
- Historical Data: Past spam activity, even infrequent, can affect reputation and trigger listing.
Key considerations
- Content Audit: Check website for unauthorized content and malicious links.
- Reputation Monitoring: Monitor domain reputation with tools like Google Search Console.
- DNS Security: Review DNS records for tampering.
- Past Activity: Be aware that even past spam activities tracked by SenderBase or similar systems may affect reputation
Technical article
Documentation from Cisco.com explains that SenderBase is the world's largest email and web traffic monitoring network. It tracks a domain's sending habits, so even infrequent past spam activity may impact reputation.
18 Oct 2021 - Cisco.com
Technical article
Documentation from MultiRBL.valli.org shares multiple reasons for listing. These can include domain hijacking, URL shortening services (using your domain), SEO poisoning, and malware distribution.
30 Jul 2024 - MultiRBL.valli.org
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