As was announced way back in 2019, the Spamhaus Project is releasing new return codes, namely error codes. The purpose is to indicate to users when Spamhaus' Public Mirrors are not protecting them. However, if users of the Public Mirrors don't configure their email infrastructure correctly, they could have some significant issues if or when an error code is returned. Read more here.

Related Information

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


How to configure your MTA to accept the Spamhaus Project’s error codes

21 February 2021

Technical Information

If you are a Spamhaus Project Public Mirror user, here's the technical information on how to configure your MTA correctly to accept error codes.

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.