The Spamhaus Project is slowly introducing error codes for users of their Public Mirrors. This indicates that IP or domain reputation data isn't returned when queried. Where an MTA isn't correctly configured to parse the error codes, email administrators can face significant problems with their email streams. These configuration guides for common MTAs help those managing email infrastructure correctly set up their MTAs to avoid issues when parsing an error code. Find them here.

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Help for Spamhaus Public Mirror Users

If you are using the Spamhaus Project’s Public Mirrors and are suddenly experiencing issues with your email stream, it is likely that you are having issues parsing newly introduced error codes.

We have collated all the information you need to help you understand what you need to do to fix the problem and find out why these error codes have been introduced.

  • What has happened to impact your email stream?
  • Why were these measures implemented?
  • What can you do to quickly resolve the issue?

Data Query Service (DQS)

Spamhaus’ Data Query Service (DQS) is an affordable and effective solution to protect your email infrastructure and users.

Using your existing email protection solution, you will be able to block spam and other related threats including malware, ransomware, and phishing emails.

The service has never failed and utilizes the longest established DNSBLs in the industry.

  • Proactive & preventative
  • Save on email infrastructure & management costs
  • Actionable


Using the Spamhaus Project’s Public Mirrors? Check your return codes now

11 February 2021


The Spamhaus Project are introducing error codes to indicate when no data is being returned. If you're using these blocklists ensure you check your MTA configuration.

Successfully accessing Spamhaus’ free blocklists using a public DNS

4 July 2018


If you're using the Spamhaus free public mirrors and Google's public DNS then it's likely your spam isn't being blocked. Here's what you need to do.

ISPs – Ensure you & your customers have continued access to Spamhaus’ DNSBLs

3 July 2018


Some ISPs, and their customers, are missing out on the opportunity to have uninterrupted access to Spamhaus's commercial blocklists. Here's how to ensure you and your customers stay protected.