Passionate about EVERYTHING email deliverability, customers are at the heart of Postmastery. Using Spamhaus’ data, Postmastery has enhanced its email deliverability optimization services by giving customers additional reputational context. We spoke with Willem Stam and Yves-Marie Le Pors-Chauvel of Postmastery to find out what this means for their customers.

About Postmastery

Created by delivery experts, for delivery experts, Postmastery has ‘empowered email senders to achieve more’ for over ten years. Now, it is recognized as a leading provider of email delivery optimization and consultancy services.

While many delivery consultants focus on the inbox, Postmastery offers a more holistic delivery approach starting from the MTA. Providing a suite of software, tooling, and consulting services, it helps ESPs, marketing agencies and brands optimize their deliverability.

Monitoring deliverability indicators

Among the key tools in Postmastery’s kit box is the Delivery Console. Particularly, its Delivery Analytics and Reputation Monitor modules, which assess delivery logs and IP/Domain reputation changes in real time.

From the moment a customer sends an email, the Delivery Console analyzes data returned by their ISP. This data is combined with several external sources, such as Google Postmaster tools, SNDS, Signal Spam and blocklist intelligence. By aggregating these varied delivery signals, customers receive a broader delivery picture to analyse. But as, Yves-Marie Le Pors-Chauvel, Deliverability Engineer, knows all too well, you can never have too many data points to build the complete picture, “We are always looking for new and interesting data signals to build in context for our customers.

Much of the data used was binary, without context to understand “why” reputation was changing. Postmastery needed more comprehensive reputational signal to quickly pivot to new areas of concern, to help with remediation, and further enhance their proactive service.

Optimizing deliverability with rich data signal

For many years, Postmastery has used Spamhaus’ Data Query Service to provide real time blocklist notifications to their customers. A robust source of binary information regarding malicious domains and IPs.

On the release of Spamhaus Intelligence API (SIA), Postmastery became one of the early adopters to gain more definitive reputational insight and further strengthen their service for customers.

This API offers dozens of metadata points relating to IPs and domains. Postmastery gained intelligence way beyond “is an asset simply good or bad”. They can better understand “why” reputation is high or low, with access to numerous signals contributing to overall reputation. This includes signal on every domain Spamhaus observes, malicious or not.

Keeping an eye on reputation

The Delivery Console now displays and monitors Spamhaus’ Reputation Score and associated data, providing a more accurate reputation picture. This means when customers’ domain reputation changes – particularly when it decreases – there is a clear indicator for investigation.

By understanding where reputation changes, how this affects deliverability, and why, customers can diagnose problems more effectively. Furthermore, the signal from SIA acts as a warning system to prevent potential listings….before a blocklist notification occurs. And the story doesn’t end there.

Armed to investigate!

Postmastery consultants analyze and assess customers’ email infrastructure, identifying potential bottlenecks and areas for improvement. They recommend, and implement, customized solutions to optimize delivery.

The rich SIA metadata provides deliverability consultants with additional context for validating and diagnosing where IP and/or domain reputation is lacking. They can then identify the impact, and the necessary remedial actions – or, in some cases, efficiently remediate Spamhaus listings!

As Yves-Marie explains, “The data reinforces our expertise and arms consultants with the data to explain what we are seeing – which is needed for customers to understand that sometimes they need to make changes to their behaviours.”

Empowering customers to succeed

For Postmastery, the success of their customers is the main driver. Willem proudly shares, “We are here to work for our customers, so if we make our customers happy, it makes us happy.

Postmastery customers now have the tools to perform a more detailed analysis armed with the Spamhaus Reputation Score and reputation metadata. And by providing a more comprehensive analysis, Postmastery has more certainty in the resolutions they deliver.

Furthermore, Postmastery has strengthened the invisible force of trust, with customers proactively asking more questions to better understand their network problems. Music to our ears.

Looking to the future…

With one foot firmly in the future, Yves-Marie left us with a thought-provoking take on managing your IP and Domain Reputation: “It helps today. But in the future, it will help more. Don’t wait, start today.” We couldn’t have put it better ourselves. Taking steps to protect IP and domain reputation now can save on valuable resources in the future.

Postmastery, we applaud your proactive approach to helping customers manage their IP and domain reputation!

Read how Postmastery leveraged Spamhaus Intelligence API and the Delivery Analytics Console to support email marketing plugin MailPoet to pinpoint specific campaigns leading to block listings.

Related Products

Spamhaus Intelligence API (SIA)

Spamhaus Intelligence API (SIA) contains context-rich metadata relating to IP and domain reputation. Integrate this data with your applications to enhance existing data feeds, or consume as an independent data source.

In this easy-to-consume format, SIA can be used for threat detection and investigation, risk scoring, customer vetting, validation and much more.

  • Save valuable time investigating and reporting
  • Simple and quick to access
  • Data you can trust in


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