How we built a load testing framework for email security at scale · Blog · Sublime Security

Mjölnir is a purpose-built load-testing framework designed to simulate realistic email-provider behavior at enterprise scale for email security platforms. The post details its producer/consumer pipeline, composable delegates for message transformation (including mailbox multiplication and message-type assignment), realistic email-address generation, a suffix-compressed radix tree with an arena allocator to manage millions of aliases efficiently, and a configurable worker pool with delay and jitter; it concludes with results validating platform capacity and lessons learned for running large-scale SMTP tests.