Sublime Security

Sublime Security builds an email security platform centered on transparency: rather than presenting detections as an opaque black-box output the way many legacy secure email gateways and cloud email security tools do, Sublime exposes a rules engine that lets security teams write, test, and audit their own detection logic in a purpose-built detection language, alongside machine-learning models for phishing, business email compromise, and malware detection. This approach lets defenders understand exactly why an email was flagged or missed, and adjust detection logic directly rather than waiting on a vendor to fix a gap.

Founded in the early 2020s and based in the Washington, D.C. area, Sublime has positioned itself as a modern alternative to traditional secure email gateways, appealing particularly to security teams with detection-engineering expertise who want direct control over their email defenses rather than accepting vendor-tuned defaults. The company maintains an open detection-rule-sharing community, allowing customers and researchers to contribute and benefit from shared detection logic in a manner similar to how open-source threat detection rules (such as Sigma or YARA) are shared in other security domains.

At the 2026 Global InfoSec Awards, Sublime Security won Hot Company in the Email Security and Management category, reflecting recognition for its transparency-first approach in a space long dominated by legacy, less-inspectable secure email gateway vendors.