Message Defense: inbound email threat detection

Message Defense reads every inbound and internal message the way an analyst would: what is being asked, who is really asking, and whether that ask fits the relationship. It catches spear phishing, business email compromise and QR-code lures without a signature.

What Message Defense evaluates

• Intent and language. Payment redirects, credential prompts, requests for secrecy and artificial deadlines, not keyword lists.
• Sender identity and infrastructure. Display-name mismatches, newly registered and lookalike domains, SPF, DKIM and DMARC posture.
• Relationship and thread context. Reply-chain reuse, injected replies and suppliers that suddenly change banking details.
• Links, attachments and QR codes. Destination analysis instead of reputation lookups alone.

Why the inbox is still the entry point

Native filtering in Microsoft 365 and Google Workspace resolves the bulk of unwanted mail. What remains is the targeted fraction: written for one recipient, sent from infrastructure too new to be on a blocklist, often with no link or attachment at all. Generative AI made that fraction cheap to produce at volume.

Live today. Deploys via API in minutes with no MX changes. Read about BEC protection and phishing protection.