Case study Halon reduces operating costs.

Web Hosting Provider
  • Reduces capital and operating expenses
  • Scales on demand securely
  • Seamlessly integrates with existing infrastructure is one of Europe's leading and most innovative web hosting providers with over one million customers in 149 countries. From multiple datacenters located in Europe and North America, hosts web servers and applications, and provide services to customers worldwide. In a comparison of web hosts, has received many industry accolades for product coverage, performance, security, and handling help and support.

Web Hosting Provider
  • Reduces capital and operating expenses
  • Scales on demand securely
  • Seamlessly integrates with existing infrastructure
The challenge: a scalable, cost-effective and secure email solution

Søren Visti Kristensen, Director of Engineering, explains,

Due to’s high growth rate, we needed to upgrade our existing email delivery and security infrastructure to a newer solution that scaled better in terms of performance and maintenance.

However, this new solution also needed to be flexible and open to integrate seamlessly into’s highly customized and optimized hosting platform. Our goal was also to reduce our expenses and offer more services with the new platform, while providing on-demand scalability in a highly secure environment without costly upgrades.

The solution: Halon typically develop their own software and systems as this enables them to offer truly differentiated services with many unique features, at very competitive prices. This usually rules out many commercial products, as they cannot properly support and integrate into’s sophisticated and highly customized platforms.

Kristensen continued,

We researched and evaluated many email security and delivery platforms against our requirements. We finally settled on Halon email platform based on price performance, ease of use, flexibility, multitenancy support with security and its ability to scale on demand

Halon’s highly integrated and comprehensive platform now comprises’s entire email delivery infrastructure; except for email storage and web mail. Halon’s primary product is an email software distribution providing a full stack, scriptable approach to functionality such as email delivery (SMTP/LMTP), routing, security (anti-spam, signing, etc), automation and integration.

It’s a flexible and scriptable email engine, designed to be run as part of a fault tolerant and linearly scalable cluster that integrates with surrounding modules and infrastructure. This highly differentiated platform enables demanding organizations like hosting providers and MSPs to implement ideal solutions for their specific needs.

On the inbound side, clusters of Halon nodes have replaced several layers of’s email gateways. The clusters perform;

  • IP reputation
  • recipient verification
  • anti-spam and antivirus
  • content filtering
  • both aliases and external forwards with SRS
  • auto replies
  • backup/replay
  • routing to the email storage servers over LMTP

all according to a REST API that wrote. The outbound cluster integrates with the same API for SASL authorization, relay permissions and rate metrics, and ensures excellent deliverability.

The logic is scripted in a way that fits their traffic sources, using techniques such as source hashing, dedicated “bulk” IPs for suspicious traffic, adaptive rate limits, queue metrics and delivery failure rates and concurrency control, all working together using scripted feedback loops.

Halon’s optimized and scriptable software also enabled to start DKIM signing all outbound messages per domain (using selector/key pairs provided by the REST API) with very little CPU overhead.

Key benefits

Reduces capital and operating expenses

Using Halon email platform we were able to consolidate and upgrade several disparate email gateways into one cost effective, feature rich and easy to manage clusters of Halon nodes. This enabled us to reduce initial capital cost, ongoing support and maintenance costs, rack space, and ongoing power and cooling requirements by up to 70%.

Scales on demand securely

Halon helped securely scale each customer on its multitenant enabled email platform and offer new services on demand and independent of each customer.

Integrates seamlessly with existing infrastructure

Halon’s platform flexible and scriptable email engine helped to integrate it seamlessly and quickly with our highly customized and optimized in house platform.