Summary
Spamhaus has updated its DBL to list individual hostnames, not just entire domains, enabling more precise spam blocking by targeting specific abusive sources. This refinement is intended to reduce false positives. However, this change requires email marketers to pay closer attention to subdomain reputation, sending practices, and list hygiene. Shared IP users face increased risks due to the actions of others. Monitoring deliverability metrics, ensuring proper authentication (SPF, DKIM, DMARC) and reverse DNS (PTR) records, and reviewing connection filter policies are critical. URL blacklists are also adapting, requiring caution with included links. In summary, the changes demand more proactive and meticulous deliverability management.
Key findings
- Hostname Specificity: Spamhaus DBL now lists individual hostnames in addition to domains.
- Increased Precision: The change allows for more targeted blocking of specific abusive hosts, reducing false positives.
- Subdomain Importance: Subdomain reputation is now more critical for email deliverability.
- Shared IP Risks: Users on shared IPs are more vulnerable to the actions of other senders.
- Increased Scrutiny: Individual sending practices face heightened scrutiny.
Key considerations
- Monitor Subdomains: Closely monitor the reputation of subdomains and sending hosts.
- List Hygiene: Maintain good list hygiene by obtaining explicit consent, providing easy unsubscribe options, and regularly cleaning the list.
- Authentication: Ensure proper email authentication (SPF, DKIM, DMARC) is configured correctly.
- Reverse DNS: Ensure proper reverse DNS (PTR) records are configured for sending hostnames.
- Monitor Metrics: Closely monitor deliverability metrics like inbox placement and bounce rates.
- Review Connection Filter Policies: Continuously review email in Connection Filter policies, this is important to ensure everything is getting through
- Careful with Links: Be careful about the links included in emails due to URL blacklist adaptations.
- Stay Updated: Keep a close eye on changes to the DBL and adjust practices accordingly.
What email marketers say
11 marketer opinions
The Spamhaus DBL (Domain Block List) has been updated to list individual hostnames in addition to entire domains, allowing for more precise identification and blocking of spam sources. This refinement aims to reduce false positives, preserving the deliverability of legitimate emails. However, it also introduces increased scrutiny on individual sending practices and subdomain reputation. Email marketers must adapt by maintaining good list hygiene, monitoring their sending reputation and deliverability metrics, and ensuring proper email authentication and subdomain usage strategies.
Key opinions
- Increased Precision: The DBL change allows for more targeted blocking of specific abusive hosts rather than entire domains, reducing false positives.
- Greater Scrutiny: Individual sending practices and subdomain reputation are now under greater scrutiny.
- Shared IP Risks: Users on shared IP addresses are more vulnerable to the actions of other senders impacting their hostname reputation.
Key considerations
- List Hygiene: Maintain good list hygiene by obtaining explicit consent, providing easy unsubscribe options, and regularly cleaning the email list.
- Reputation Monitoring: Closely monitor sending reputation and deliverability metrics, such as inbox placement rates and bounce rates.
- Authentication: Ensure proper email authentication (SPF, DKIM, DMARC) is correctly configured.
- Subdomain Strategy: Reconsider subdomain usage, potentially separating marketing and transactional emails to isolate reputation risks.
- Stay Updated: Keep a close eye on changes to the DBL and adjust practices accordingly.
Marketer view
Email marketer from EmailVendorSelection states that the Spamhaus DBL change means increased scrutiny on individual sending practices. Marketers must ensure they are not engaging in activities that could lead to hostname blacklisting, like sending unsolicited emails or having poor list hygiene.
8 May 2023 - EmailVendorSelection.com
Marketer view
Email marketer from Gmass recommends double checking your email authentication is correct to ensure they are not impacted, this includes SPF, DKIM and DMARC records are configured correctly.
13 Oct 2023 - Gmass.co
What the experts say
3 expert opinions
Spamhaus is updating its Domain Block List (DBL) to include individual hostnames in addition to domains. This change provides a more precise method for identifying and blocking spam sources, reducing the likelihood of legitimate domains being incorrectly blocked. As a result, email marketers need to closely monitor the reputation of their subdomains, as a compromised subdomain can negatively impact deliverability even if the primary domain maintains a positive reputation.
Key opinions
- Hostname Listing: Spamhaus DBL now includes individual hostnames.
- Improved Accuracy: More accurate identification of spam sources reduces false positives.
- Subdomain Importance: Subdomain reputation is now more critical for email deliverability.
Key considerations
- Monitor Subdomains: Email marketers should closely monitor the reputation of their subdomains.
- Prevent Compromises: Take steps to prevent subdomains from being compromised or used for spam activities.
- Address Deliverability: Be prepared to address deliverability issues that may arise from a compromised subdomain, even if the main domain is reputable.
Expert view
Expert from Spam Resource explains that Spamhaus listing hostnames in the DBL provides a more accurate way to identify and block spam sources. This reduces the risk of false positives where legitimate domains are blocked due to the actions of a few bad actors.
27 Dec 2023 - Spam Resource
Expert view
Expert from Email Geeks shares that Spamhaus is changing the DBL to list hostnames and not just domains.
23 Apr 2024 - Email Geeks
What the documentation says
5 technical articles
Spamhaus is updating its DBL (Domain Block List) to include individual hostnames in addition to domains, enabling more precise blocking of spam sources. This change necessitates that email marketers monitor hostname reputation, paying closer attention to individual subdomains and sending hosts. URL blacklists like URIBL are adapting to reflect hostname reputation, requiring careful attention to links in emails. Ensuring proper reverse DNS (PTR) records for sending hostnames is crucial, and monitoring connection filter policies is also important to prevent bulk email issues.
Key findings
- Hostname Specificity: Spamhaus DBL now lists hostnames, not just domains.
- Reputation Shift: Email marketers must monitor hostname reputation, not just domain reputation.
- URL Blacklist Adaptation: URL blacklists are adapting to reflect hostname reputation.
Key considerations
- Monitor Hostnames: Pay closer attention to the reputation of individual subdomains and sending hosts.
- Careful with Links: Be more careful about the links included in emails due to URL blacklist adaptations.
- Proper DNS: Ensure proper reverse DNS (PTR) records are configured for sending hostnames.
- Filter Policies: Continuously review email in Connection Filter policies, this is important to ensure everything is getting through.
Technical article
Documentation from Spamhaus explains that the DBL (Domain Block List) will now list individual hostnames in addition to domains. This provides greater precision in blocking spam sources, targeting the specific abusive host without penalizing the entire domain.
20 Dec 2022 - Spamhaus.com
Technical article
Documentation from Microsoft shares that they are constantly updating their connection filter policies to help prevent bulk email. It is important to use this to review all your emails and ensure they are getting through.
1 Apr 2023 - Microsoft.com
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How does Spamhaus decide whether to list a subdomain or a whole domain on the DBL?
