What Sublime Security does
Sublime Security is an AI-native email security platform built for an era where attackers can mass-produce convincing phishing, BEC, and account-takeover campaigns with LLMs. Sublime sits in the email path and runs every message through a stack of detection agents — visual layout analysis, sender behavior, identity graph, content reasoning — and issues a verdict in milliseconds, with full transparency on why a message was blocked or released. Unlike legacy SEGs and bolt-on email security tools, Sublime exposes its detection logic as Message Query Language (MQL) rules so that security teams can write, share, and audit detections like code.
In 2025 Sublime launched the industry's first autonomous AI email defense agents, which triage user-reported phish, hunt across mailboxes, and contain incidents without analyst intervention.
Who it's for
Sublime Security sells to security operations teams at enterprises and security-mature mid-market companies. Disclosed customers include Spotify, Snowflake, Zscaler, Anduril, SentinelOne, Compass, British Gas, Centrica, Benteler, and Elastic. Sublime is positioned as a primary or augmenting layer alongside Microsoft 365 and Google Workspace email security.
Pricing
Sublime Security is sold as an enterprise subscription priced by mailbox volume and feature tier (free community edition for individual users, paid Core and Premier tiers for orgs). A free community version of the platform is publicly available.
Team & funding
Sublime Security was founded in 2020 by Josh Kamdjou (CEO, former offensive security operator), with Ian Thiel as co-founder. The company raised a $9.8M seed in 2023, a $20M Series A in May 2024 led by Index Ventures (with Decibel Partners and Slow Ventures), a $60M Series B in December 2024 led by IVP (with Citi Ventures and Index), and a $150M Series C in October 2025 led by Georgian (with Avenir, 01A, Index, IVP, Citi Ventures, and Slow Ventures). Cumulative funding sits at roughly $244M. Sublime reported 100% YoY ARR growth in H1 2025.
Position vs competitors
Sublime competes with Abnormal Security, Material Security, Mimecast, Proofpoint, and Microsoft Defender for Office. Its differentiators are MQL transparency, the open detection community, and the new autonomous defense agents.