StrongestLayer
StrongestLayer provides AI email security for Microsoft 365 and Google Workspace.
- Categories
- Email security
- Based in
- San Francisco, United States
- Founded
- 2024
- Ownership
- Private
- Certifications
- SOC 2
About StrongestLayer
StrongestLayer sells AI-native email security for Microsoft 365 and Google Workspace. It targets organisations that need to catch phishing and business email compromise that passes through existing secure email gateways. The company says its system reads the intent behind each message rather than relying on signatures or patterns. It checks what an email is asking for, how it evaded filters, and why it would work on the recipient. Verdicts are delivered in about thirty seconds with reasoning and evidence. The platform integrates via API without MX changes and is live in fifteen minutes. It also offers professional services for law firms, accounting firms, and consulting or M&A firms. The company was founded in 2024 and is backed by Sorenson Capital and Recall Capital.
Products
- Inbox AdvisorAn add-in for Outlook and Gmail that gives a plain English verdict on each email, such as safe to trust, caution, or block, with reasons.
- Threat TriageA tool that presents pre-investigated alerts with explainable verdicts so security operations teams can close cases quickly.
- Threat HuntA search function that sweeps all protected mailboxes by sender, subject, URL, or domain to find related emails across the organisation.
- TRACE platformThe Threat Reasoning AI Correlation Engine that powers the company's email security by reasoning about each message.
Ownership and deals
- Raised $4.1m in a seed roundInvestor Inovia CapitalReport on the StrongestLayer funding round of July 2026 (opens in a new tab)
- Raised $5.2m in a seed roundInvestor Sorenson CapitalReport on the StrongestLayer funding round of July 2025 (opens in a new tab)
Acquisitions come from SecurityWeek's monthly M&A round-ups from 2021 onwards, from Cybersecurity Ventures' quarterly M&A reports for 2020, and a few from Wikipedia lists. Funding rounds from 2022 onwards come from Return on Security's weekly Security, Funded newsletter. These are dated to the month. A few deals added from the news are dated to the day. Smaller deals may be missing. Amounts are in US dollars.