Summary
Sudden Spamhaus IP listings can be caused by a variety of factors, including temporary glitches within Spamhaus itself, compromised accounts sending spam, sudden increases in email volume or spam complaints, poor list hygiene leading to high bounce rates, sending unsolicited emails, or misconfigured email authentication settings (SPF, DKIM, DMARC). Additionally, Spamhaus lists IPs involved in sending or supporting spam, including hosting spammed websites. Poor data quality causing bounces and spam traps, non-RFC compliant email practices, and compromised systems contribute to the issue. Resolution requires identifying the cause, requesting delisting, improving sender reputation, implementing strong email authentication, ensuring compliance with anti-spam laws, and monitoring sender reputation.
Key findings
- Spamhaus Glitches: Temporary glitches within Spamhaus can cause IPs to be briefly listed and then removed.
- Compromised Accounts: Compromised accounts or malware infections can lead to unauthorized spam sending, triggering listings.
- List Hygiene: Poor list hygiene practices, such as high bounce rates and spam complaints, contribute to blacklisting.
- Volume Spikes: Sudden increases in email volume or spam complaints can raise suspicion and lead to listings.
- Authentication Issues: Improperly configured or missing email authentication (SPF, DKIM, DMARC) can negatively impact sender reputation.
- Spam Traps: Sending emails to spam trap addresses damages sender reputation.
- Involvement in Spam: Involvement in sending or supporting spam activities, directly or indirectly, can cause listings.
- Poor Data Quality: Poor data quality from old or incorrect information, contributes to bounces and spam traps.
- Non-Compliance: Non-RFC Compliant emails with incorrect information are a key finding.
Key considerations
- Investigate and Resolve: Identify the root cause of the listing, whether it's a glitch, compromised account, poor list hygiene, technical misconfiguration, or spam activity.
- Improve Sender Reputation: Implement best practices for email sending, including double opt-in, valuable content, and list segmentation, to improve sender reputation.
- Monitor Sending Practices: Actively monitor sender reputation, bounce rates, and spam complaints to proactively address potential issues.
- Ensure Compliance: Ensure that email sending practices comply with anti-spam laws and regulations.
- Implement Authentication: Implement and properly configure SPF, DKIM, and DMARC to authenticate email and protect against spoofing.
- Request Delisting: Request delisting from Spamhaus once the underlying issue has been resolved.
- Remediate Security: Ensure that there is remediation against spam and compromises.
- Data Quality: Improve data quality, removing incorrect or old information.
What email marketers say
9 marketer opinions
Sudden Spamhaus IP listings are often caused by a variety of factors including: Spamhaus issues that may be temporary, compromised accounts or malware infections leading to spam being sent, sudden spikes in email volume, poor list hygiene resulting in high bounce rates and spam complaints, sending unsolicited emails, and issues with email authentication such as SPF, DKIM, and DMARC. Improving data quality, monitoring sender reputation, and ensuring compliance with anti-spam laws are crucial for preventing and resolving these listings.
Key opinions
- Compromised Accounts: Compromised accounts and malware infections can lead to unauthorized spam sending, triggering Spamhaus listings.
- List Hygiene: Poor list hygiene practices, such as high bounce rates and spam complaints, contribute to blacklisting.
- Email Volume Spikes: Sudden increases in email volume can raise suspicion and lead to temporary or prolonged listings.
- Authentication Issues: Improperly configured or missing email authentication (SPF, DKIM, DMARC) can negatively impact sender reputation.
- Spam Traps: Sending emails to spam trap addresses can severely damage sender reputation and result in listings.
- Data Quality: Poor data quality causes bounces and spam traps.
Key considerations
- Investigate and Resolve: Identify the root cause of the listing, whether it's a compromised account, poor list hygiene, or technical misconfiguration.
- Improve Sender Reputation: Implement best practices for email sending, including double opt-in, valuable content, and list segmentation, to improve sender reputation.
- Monitor Sending Practices: Actively monitor sender reputation, bounce rates, and spam complaints to proactively address potential issues.
- Ensure Compliance: Ensure that email sending practices comply with anti-spam laws and regulations.
- Implement Authentication: Implement and properly configure SPF, DKIM, and DMARC to authenticate email and protect against spoofing.
- Data Quality: Improve data quality, removing incorrect or old information.
Marketer view
Email marketer from Mailjet explains that sudden IP listings and blacklists are sometimes caused by a sudden spike of spam complaints, a increase in spam traps being hit or a sudden increase in volume.
5 Oct 2022 - Mailjet
Marketer view
Email marketer from Email Geeks confirms that there was definitely something going on at Spamhaus this morning with many clients listed but quickly removed.
18 Sep 2021 - Email Geeks
What the experts say
3 expert opinions
Sudden Spamhaus IP listings can stem from various causes, including Spamhaus-side glitches resulting in temporary listings, sudden spikes in spam complaints, compromised accounts sending spam, and misconfigured email authentication settings. Proactive monitoring of sender reputation is also crucial for identifying and addressing deliverability issues before they escalate into blacklistings.
Key opinions
- Spamhaus Glitches: Temporary listing glitches can occur on the Spamhaus side, causing IPs to be listed and then quickly removed.
- Spam Complaints: A sudden increase in spam complaints can trigger blacklisting.
- Compromised Accounts: Compromised email accounts can be used to send spam, leading to IP listings.
- Authentication Issues: Misconfiguration of email authentication settings can negatively impact sender reputation.
- Sender Reputation: It is important to proactively monitor your sender reputation.
Key considerations
- Investigate Listing Cause: Determine the reason behind the listing, whether it's a Spamhaus glitch, spam complaints, compromised accounts, or authentication issues.
- Implement Authentication: Ensure correct configuration of email authentication settings to improve deliverability.
- Monitor Reputation: Proactively monitor sender reputation and deliverability metrics to identify potential problems.
- Remediate Security: Consider improving security to stop compromised accounts.
Expert view
Expert from Email Geeks confirms that there may have been a listing glitch on Spamhaus today where a bunch of IPs were listed briefly and then removed.
13 Oct 2023 - Email Geeks
Expert view
Expert from SpamResource explains that a sudden blacklisting can be caused by a sudden increase in spam complaints, a compromised account sending spam, or a misconfiguration of email authentication settings.
13 Feb 2024 - SpamResource
What the documentation says
6 technical articles
Spamhaus IP listings are primarily due to involvement in sending or supporting spam, which can include direct spam sending, hosting spammed websites, or providing services to spammers. The CSS list specifically identifies IPs with poor reputations based on spam activity, botnet infections, or malware distribution, often stemming from compromised systems. Resolution involves identifying and fixing the root cause, requesting delisting, and implementing preventative measures. Additionally, non-RFC compliant email practices like incorrect dates and headers, as well as improper SPF/DKIM records, can contribute to listings due to concerns about server control and potential spam origins.
Key findings
- Involvement in Spam: IPs are listed for direct or indirect involvement in spam activities.
- Compromised Systems: Compromised systems and networks contribute to poor IP reputation and CSS listings.
- Non-Compliance: Non-RFC compliant email practices can signal spam and lead to listings.
- Improper Authentication: Incorrect SPF/DKIM records indicate a lack of server control and increase the likelihood of being listed.
- CSS Listings: Poor IP reputation resulting from botnet infections and malware distribution lead to IPs being listed on the CSS.
Key considerations
- Identify and Resolve: Determine the cause of the listing by searching for spam activity and compromised systems.
- Request Delisting: Request delisting through the Spamhaus website after resolving the issue.
- Prevent Future Occurrences: Implement measures to prevent future spam activity and maintain a clean IP reputation.
- Ensure RFC Compliance: Verify that email practices comply with RFC standards, including correct dates and headers.
- Implement SPF/DKIM: Correctly set up SPF/DKIM records to assert server control and prevent spoofing.
Technical article
Documentation from Spamhaus explains that IPs and domains are listed due to involvement in sending or supporting spam. This includes direct spam sending, hosting spammed websites, or providing services to spammers.
1 Sep 2021 - Spamhaus
Technical article
Documentation from Spamhaus shares that the CSS (Composite Spam Score) lists IPs that have a poor reputation based on spam activity, botnet infections, or malware distribution. It is often due to compromised systems within the network.
6 Dec 2022 - Spamhaus
Besides Spamhaus, what blocklists are important for email marketers to monitor?
How can I get delisted from Spamhaus?
How can I report fraudulent emails and domains to Spamhaus and other relevant organizations?
How do I check Spamhaus for my IP address and understand the listings?
How do I get help with a Spamhaus CSS delist?
How do I prevent my IP address from being listed in the Spamhaus CSS database?
