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Where to apply Spamhaus blocklists for effective email filtering

Spamhaus produces many different DNSBLs (blocklists).  The question is which ones to apply where? This simple guide provides you with all the information you need.

Tools and Plugins

Access the free testing tool for DNSBL users: The Blocklist Tester

Use the Blocklist Tester (BLT) to check if your email servers are correctly configured to use the Spamhaus Blocklists.

The BLT sends a series of test emails to your nominated email address. If your server is correctly set up to query our blocklists, all the emails should be rejected. The BLT provides a summary of exactly what emails have been rejected or delivered.

Get the SpamAssassin plugin 

Find how to use DQS at its best with the Apache Foundation's open-source anti-spam platform, SpamAssassin. Find the plugin and configuration files here.

Get the Rspamd plugin

Find how to use DQS at its best with the open-source anti-spam platform, Rspamd. Find the plugin and configuration files here.

Technical Documentation

Configuration examples

Whether you're looking for guidelines on filtering SMTP sessions or want to know how to use DQS with an MTA, this will have you covered.

Understanding Spamhaus Data 

From definitions and acronyms to how to use the data in a real-world scenario - this is a great introduction to our data.

Additional Resources

To help you get set up_Highlight
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Getting the most from email filtering


Top 10 (+1) tips for running your own email server

Best Practice

Getting DNSBLs and email filtering right


Understanding a malicious email's source code

Malcious Email-Source Code-Email Filtering Best Practice
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DBL increasing accuracy with Hostnames 

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Why you should use domain and hash blocklists


Email blocklists – buy cheap, buy twice!


Beyond IP and Domain Reputation



Managing your subscription

To review and manage your subscription, simply login to the Spamhaus portal. From the portal, you'll also be able to review usage, FAQs, and the DQS manual. Login details should have already reached your inbox from