A validation engine
you actually own.
MXGuard verifies whether an email address is real and deliverable — without sending an email. It runs on your servers, hits external SMTP servers from your IP space, and returns a clear classification. No third party ever sees your customer lists.
Everything you need.
Nothing you don't.
Multi-node architecture
Run independent MX and SMTP node pools across regions. Add capacity by adding servers — no license upgrade required.
Six clear classifications
Deliverable · Catch-all · Undeliverable · Disposable · Risky · Unknown. Every result includes a confidence score.
Full source code
Audit, patch, fork. Optional source-code escrow for Enterprise.
Privacy by architecture
Your data never leaves your servers. There is no MXGuard cloud — there's no cloud to leak from.
REST API + Dashboard
OpenAPI-spec'd HTTP API plus a React-based admin UI. CSV bulk import, webhook dispatch, queue management.
Provider-aware SMTP
Per-provider strategies for Gmail, Microsoft 365, Yahoo, custom relays. Proxy rotation built in.
Six steps.
Sub-second latency.
Submit
Email arrives via REST API, CSV upload, or webhook.
Pre-checks
Syntax (RFC 5321/5322), disposable list match, role-account detection.
MX lookup
DNS resolution against your MX node pool. Catch-all probe if domain is suspicious.
SMTP probe
RCPT TO handshake from your SMTP node pool. Provider-aware strategy applied.
Classify
One of six labels with a confidence score and a full audit trail.
Deliver
Result returned via API response, webhook, or batch CSV — your choice.
What you're
actually deploying.
Built for teams
that take ops seriously.
Email-platform builders
You're shipping an email-marketing, CRM, or outreach product. Validation is a feature you need to own — not a third-party dependency in your hot path.
High-volume senders
You send millions of emails per month. Per-email validation pricing is bleeding you. One license pays back inside 90 days.
Compliance-bound teams
You can't ship customer email lists to a US SaaS. Self-hosted means data stays inside your VPC, your region, your audit boundary.
Internal tooling teams
You're building list-hygiene into an internal CRM or back-office tool. Drop in the engine, ship the feature, move on.
Ready to deploy?
Get your license. Deploy on your servers. Validate unlimited emails. Pay once, own forever.