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 One.com’s email gateways. The clusters perform;
- IP reputation
- recipient verification
- anti-spam and antivirus
- both aliases and external forwards with SRS
- auto replies
- routing to the email storage servers over LMTP
all according to a REST API that One.com 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 One.com to start DKIM signing all outbound messages per domain (using selector/key pairs provided by the REST API) with very little CPU overhead.