Your email filter is letting threats through.
MailThreatZero runs five independent scanning layers before anything reaches your inbox — network reputation, authentication, virus and macro detection, spam analysis, and optional AI. No per-user fees.
Five layers, independently verified
Each stage runs regardless of what the previous one found. No skipped checks, no single point of failure.
Network
Six RBL/DNSBL lookups. IP reputation scored against known bad actors. GeoIP filtering and rate limiting. Connections from compromised hosts die here before we parse a single header.
Authentication
SPF, DKIM, and DMARC — all three, enforced. Not just checked and logged. Spoofed senders don't reach content scanning.
Malware
ClamAV with official and unofficial signatures, Linux Malware Detect, and Oletools for Office macro analysis via Rspamd. Attachments are inspected, not trusted.
Spam & Content
SpamAssassin (550+ rules) plus Rspamd with Pyzor and Razor2 collaborative fingerprinting, Bayesian filtering, and URL reputation on every link. Dedicated phishing, header, and content filters catch lookalike/homograph domains, spoofed headers, and mismatched links — and stand down automatically for senders that pass SPF/DKIM/DMARC, so legitimate newsletters and billing mail aren't penalized for normal bulk-sender patterns.
AI Layer
Optional. Claude Haiku 4.5 / Sonnet 5 / Opus 4.8, or GPT-4o mini / GPT-4o — your API key, your cost, zero markup. Activates only when Phase 1 scores stay below threshold. Catches phishing and BEC that rules miss.
Built to be watched
Full visibility into every message: live mail flow, per-domain policies, quarantine management, and filter breakdown per message. The React interface doesn't require a manual to operate.
What makes us different
Serious filtering without the complexity or the per-user pricing games.
No per-user pricing
You pay per domain. A domain with 5 users costs exactly the same as one with 500. Scale your organization without watching a billing counter climb.
Transparent AI costs
You supply the API key. You pay OpenAI or Anthropic directly, at their listed rates. We don't mark it up and call it "intelligent filtering."
Works with any mail server
SMTP relay configuration. Compatible with Exchange, Office 365, Google Workspace, Postfix, Dovecot — anything that speaks SMTP. Setup takes under an hour.
Full filter visibility
See exactly which filters fired, what scored, and why a message was quarantined — per message, not just "blocked by spam filter." Logs that actually help you debug.
Fewer false positives
Authentication-aware scoring recognizes senders that pass SPF, DKIM, and DMARC and stops penalizing them for normal newsletter and billing-mail patterns. Real threats still score; legitimate mail stays out of quarantine.
Office macro & spam-trap defense
Oletools inspects Office attachments for malicious VBA macros, and honeypot spam-traps feed live sender reputation — surfacing campaigns before they reach real inboxes.
Stop guessing what your filter is doing.
Month-to-month. No setup fees. Deployed and filtering in under an hour.