The Spamhaus Project


If you query the legacy DNSBLs via DigitalOcean move to Spamhaus Technology's free Data Query Service

If you are currently accessing the free DNS Blocklists (DNSBLs) via the Public Mirrors, and you’re using DigitalOcean infrastructure - you'll need to make some minor changes to your email infrastructure. The changes are easy to implement, but if you fail to do so, you could find that at some point post-February 14th 2024, all or none of your email is blocked!

by The Spamhaus TeamFebruary 15, 20243 minutes reading time

Jump to

The headlines for those in a hurry

The headlines for those in a hurry

The Terms of Use state that users cannot query via DNS resolvers where there is no attributable reverse DNS; this includes DigitalOcean (we’ll explain why later in this article).

To provide a clear signal to these users that these blocklists are not protecting their email, an error code will be returned; If you haven’t set up your email servers to accept this error code, all emails could be rejected and bounced back to their sender.

To prevent any issues with your email stream, stop accessing the free blocklists via the Public Mirrors and start accessing the blocklists via Spamhaus Technlogy's free Data Query Service (DQS), which you can sign up for here.

Once you’ve verified your email address, you will get access to a “DQS key” to include in your configuration. These config changes take only minutes; see our technical docs for more detail.

Why isn’t the Spamhaus Project allowing DigitalOcean users to query its public blocklists?

The blocklists that are made freely available via the Public Mirrors are for small-scale, non-commercial use. To ensure these users have a good quality of service, usage is monitored and measured against the Project’s Terms of Use.

DigitalOcean masks organizations’ queries to the Public Mirrors, so the team can’t attribute usage to individual entities. There is no way of establishing the number of queries a single organization is making.

To provide transparency, these free blocklists can be accessed via Spamhaus Technology's free DQS.

How is Spamhaus Technology's free DQS different from the free Public Mirrors?

How to access the free DQS

  1. Sign up for an account
  2. Verify your email address
  3. Log in to your account and access your DQS key
  4. Update your email configuration. We have config guides for mainstream MTAs.

How will DigitalOcean users be prevented from querying the free DNSBLs?

To ensure the Terms of Use are adhered to, queries from a specific IP address outside the policy will be blocked, and an error code will be returned. In the case of querying via an open/public resolver, i.e., DigitalOcean, the error code is

If your MTA can’t correctly parse these error codes, serious issues can occur, including bouncing all emails back to their senders and your emails not being queried against the blocklists. Here’s how to properly configure your MTA to process these error codes, if you continue to use the Spamhaus Project’s DNSBLs.

When will the error code for DigitalOcean DNSBL users be introduced?

The error code will be slowly implemented across DigitalOcean’s IP space, commencing from Wednesday, February 14th, 2024.

Please don’t delay – take action now and move to Spamhaus Technology's free DQS.

What if I don’t want to use the free DQS?

Use DNS resolvers with attributable DNS to continue being protected by Spamhaus’s IP and domain reputation.

If you no longer wish for your mail stream to be protected by the free blocklists, remove all associated configurations from your email infrastructure.

Further details

Additional information for DNSBLs users having issues due to error codes is detailed here.

Previous communications that were sent in relation to these changes can be found here:

Any questions?

Not a problem – reach out to us via Twitter @spamhaus.