Sublime Security announced a $60 million Series B on December 12, 2024, led by IVP, with Citi Ventures, Index Ventures, Decibel Partners, and Slow Ventures participating. The round was a financing milestone for the enterprise email-security company—not a measure of its product performance. Sublime later announced a $150 million Series C in October 2025, so the 2024 Series B is not its latest funding round.
Who participated in Sublime’s Series B?
Sublime founder and CEO Josh Kamdjou announced the round on December 12, 2024, naming IVP as lead investor and Citi Ventures, Index Ventures, Decibel Partners, and Slow Ventures as participants. SecurityWeek reported that the financing brought Sublime’s total raised to $93.8 million at that time. That figure is a historical funding total, not a current one. Sublime’s announcement and SecurityWeek’s report cover the round.
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What does Sublime Security do?
Sublime sells email-security software for Microsoft 365 and Google Workspace. Contemporary coverage described a platform that combines AI-assisted detection with a rules engine to help security teams investigate threats and respond to suspicious messages. Reported threat categories included phishing, malware, and targeted business email compromise. Those are product descriptions, not independent findings about detection accuracy or effectiveness. SecurityWeek’s 2024 report describes the platform.
Rules that teams can customize
Sublime’s product materials highlight Message Query Language (MQL), an open language for writing, running, customizing, and sharing detection and response rules. The company describes its approach as pairing machine-learning models with configurable rules, offering security teams more visibility into how detections are defined and the ability to tailor them. The company’s launch post explains its MQL approach.
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Investigation and response workflows
Reported workflows include threat hunting, triage of messages flagged by users, and configurable actions such as quarantining a message or adding a warning banner. The appeal for an organization depends on its existing email environment, how much it wants to customize detection logic, and how it handles investigation and remediation. The available product descriptions do not establish a neutral comparison with competing platforms or quantify performance.
What did Sublime offer when the Series B was announced?
At launch in February 2023, Sublime described a free, self-hosted Core product alongside paid SaaS and Enterprise offerings. SecurityWeek reported in December 2024 that the first 100 inboxes were free in Sublime’s SaaS environment. These are historical descriptions; they do not establish current pricing, limits, or deployment terms. The 2023 launch announcement and the 2024 report provide the dated details.
How does the Series B fit into Sublime’s funding history?
| Date | Funding milestone | Lead and participants named in the announcement or report |
|---|---|---|
| February 22, 2023 | $9.8 million at launch | Led by Decibel Partners and Slow Ventures |
| April 24, 2024 | $20 million Series A | Led by Index Ventures |
| December 12, 2024 | $60 million Series B | Led by IVP; Citi Ventures, Index Ventures, Decibel Partners, and Slow Ventures participated |
| October 28, 2025 | $150 million Series C | Led by Georgian; named participants included Avenir, 01A, Jon Oberheide, Nicole Perlroth, Index Ventures, IVP, Citi Ventures, and Slow Ventures |
The company announced the Series A and Series C in its own posts: April 2024 Series A and October 2025 Series C. The Series B and its contemporaneous total-raised figure were also covered by SecurityWeek.
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What does the funding mean for customers and investors?
The round shows that investors committed capital to Sublime in 2024; by itself, it does not demonstrate that the product outperforms alternatives, that customers will achieve a particular security outcome, or that the company will deliver a financial return. For organizations assessing the software, the relevant questions are practical: whether it supports their email environment, whether its detection rules are sufficiently transparent and customizable, and whether its investigation and response workflows fit their operations.
At the time, Sublime said it served enterprise customers including Elastic, Benteler, and Cribl, and named Spotify, Reddit, and Brex among existing users, as reported by SecurityWeek. Those are company-reported customer examples, not independently audited adoption figures. The company’s funding announcement also included a testimonial from Benteler’s Security Operations Lead Jonas Eichinger; it is a customer statement published by Sublime, not an independent product evaluation. Sublime’s Series B post includes the testimonial.
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What changed after the 2024 round?
In October 2025, Sublime announced a $150 million Series C led by Georgian. In April 2026, it said it was moving to a 100% channel-sales model, describing value-added resellers as services-led partners. The channel announcement signals a change in how Sublime intends to sell; it does not establish the availability or terms of any referral or affiliate program. The Series C announcement and the channel-sales announcement set out those later developments.
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