beforetheycostyoumoney.
Mailsurity analyzes email, domain, reputation, and behavioral signals, then decides whether to allow, verify, or block the user. It catches disposable, temporary, and fake addresses, including brand-new ones other checkers haven't seen yet.
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Trusted by fast-growing teams
Disposable domains tracked
Detection accuracy
p99 API latency
Free checks to start
Disposable domains tracked
Detection accuracy
p99 API latency
Free checks to start
Everything you need to keep junk out
A detection system built for SaaS teams, newsletter authors, and course creators. Only real users make it through.
Always-fresh domain list
We source 220k+ disposable, temp-mail, and burner domains from public feeds and live throwaway providers, then update the list automatically so stale entries never sneak past.
AI fallback for gray-zone domains
When heuristics land in the gray zone, an LLM breaks the tie. Verdicts are cached 30 days, so you only pay the latency cost once per new domain.
MX + entropy heuristics
We resolve MX, score local-part entropy and brand-similarity, and track cluster reputation to catch brand-new throwaway domains that no list has yet.
Bulk CSV checks
Upload an existing email list from the dashboard and get an enriched CSV back with classification, confidence and source per row. Great for scrubbing mailing lists.
One endpoint, any stack
POST an email, get a JSON verdict. No SDK, no schema migrations. Drops into Next.js, Laravel, Django, or any HTTP client in minutes.
Per-team allow / deny rules
Override the global verdict for your own domains: add corporate addresses to an allow-list, or block known vendor domains. It runs in the same hot path, with zero extra latency.
From email to verdict in one round trip
No async pipeline. No webhook setup. The API returns a full verdict synchronously, so you can block fake emails before the user ever sees a confirmation screen.
Add one line to your signup
Drop a single POST call into your registration flow. Works with any language or framework: curl, Node, Python, PHP. No SDK, no schema changes, no webhooks.
We run a 5-layer check
Curated list → 30-day cache → MX + entropy heuristics → AI fallback. Most responses return in under 20ms; the AI only runs on first-seen gray-zone domains.
Block, allow, or flag
Get a structured verdict: classification, confidence score and the reason behind it. Block fake signups, scrub your mailing list, or flag risky accounts for review.
Ship in one curl
No SDK to install, no schema migrations to run. Send an email, get a risk score and a resolved ALLOW / VERIFY / BLOCK decision, not just a boolean.
curl -X POST https://mailsurity.com/api/assess \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"email": "abc@temporary-domain.example"}'{
"check_id": "0f3c1e6a-1234-4a11-9c2e-8b6f2a5d9e10",
"email": "abc@temporary-domain.example",
"risk_score": 93,
"confidence": 88,
"decision": "BLOCK",
"signals": {
"disposable": true,
"mx_valid": true,
"domain_age_days": 4,
"role_account": false,
"free_provider": false
},
"reasons": ["Disposable email provider", "Domain registered 4 days ago"]
}Full request & response schema, decision bands, team-tunable thresholds, and copy-paste examples in cURL, JavaScript and Python.
Read the Decision API referenceAudit your signup list for disposable emails
Paste a batch of signup emails or domains and see how many are disposable, legitimate, or unknown in seconds. The part before the @ never leaves your browser.
- Spot throwaway accounts hiding in your existing list
- See the projected cost of letting them through
Predictable plans, no surprise overages
Pay per month, not per request. Hard caps so you'll never see a surprise bill, plus 500 free checks to start, no credit card needed.
Free
Try it risk-free. No card required.
- 500 checks to start
- Live API + dashboard
- Full detection cascade
- Email support
Starter
For indie apps and side projects getting started.
- 5,000 checks / month
- CSV bulk check
- Team allow / deny lists
- AI gray-zone fallback
Growth
For growing products that need reliable email hygiene.
- 25,000 checks / month
- Everything in Starter
- Lower cost per check
- Email support
Scale
For high-volume teams that need more headroom.
- 100,000 checks / month
- Everything in Growth
- Priority support
- Higher rate limits
All plans include the full detection cascade: list, cache, heuristics, and AI fallback.
Questions, answered
Keep your funnel clean.
Start in minutes.
One API call is all it takes. Protect your SaaS signups, newsletter list, or course enrollments from throwaway emails before they ever reach your database.