Now verifying 40M+ emails / month
Know which emails are real
before they cost you.
Catch disposable addresses, spam traps, and dead inboxes at signup — not three months later in your bounce report.
Try: test@mailinator.com, hello@gmail.com, info@company.com
99.2%
Accuracy
<300ms
Avg response
250+
Disposable domains tracked live
40M+
Checks per month
Platform
Everything a signup form needs to trust an email
One API. Six checks. A verdict you can act on in real time.
Disposable & Temp-Mail Detection
Flags Mailinator, Guerrilla Mail, 10-minute-mail, and 20,000+ other known throwaway domains, updated daily.
Syntax & MX Validation
Confirms the address is well-formed and its domain actually accepts mail before you ever send one.
SMTP Deliverability Check
Pings the receiving mail server directly to confirm the mailbox exists, without sending an email.
Role-Based & Catch-All Detection
Flags info@, admin@, and catch-all domains that accept everything and tell you nothing.
Spam-Trap Risk Scoring
Cross-references known spam-trap patterns so a bad send doesn't torch your sender reputation.
Real-Time Signup Webhook
Drop a webhook into your signup form and block bad emails before they ever hit your database.
Workflow
From address to verdict in five steps
Submit
Send one email, paste a list, or wire up the real-time API.
Syntax & Domain Check
We validate formatting and confirm the domain resolves and accepts mail.
Deep Verification
MX, SMTP, disposable-domain, and role-based checks run in parallel.
Verdict & Score
You get a stamped verdict plus a 0–100 deliverability score.
Act On It
Block at signup, auto-clean before a send, or export — enforced by your rules.
Live Metrics
Built to be trusted with your list
Detection Accuracy
Checks Processed / mo
Avg Response Time
Disposable Domains Tracked
False-Positive Rate
Lists Cleaned / mo
Pricing
Start free, pay for what you verify
Every plan includes disposable detection, MX/SMTP checks, and API access. No hidden per-seat fees.
Free
Explore OpenGuardian, no card required.
1,000 verifications
- ✓ Real-time single-check API
- ✓ Disposable + MX/SMTP checks
- ✓ Community support
- ✓ 7-day trial
Starter
For indie devs and small apps.
10,000 verifications/mo
- ✓ Bulk list upload
- ✓ Disposable + MX/SMTP checks
- ✓ Email support
Growth
For growing signup funnels.
100,000 verifications/mo
- ✓ Real-time webhook
- ✓ Spam-trap risk scoring
- ✓ Zapier/Segment integrations
- ✓ Priority support
Scale
For high-volume senders.
1,000,000 verifications/mo
- ✓ Dedicated IP allowlisting
- ✓ Advanced analytics
- ✓ SLA-backed uptime
- ✓ Dedicated support
Enterprise
For platforms verifying at massive scale.
Custom pricing
- ✓ Private deployment option
- ✓ Custom disposable-domain rules
- ✓ SSO/RBAC
- ✓ Audit logs
- ✓ Dedicated account manager
Trusted by teams like yours
“We were losing 8% of our list to disposable addresses every month. OpenGuardian catches them at signup now — our bounce rate dropped to under 1%.”
Ananya Rao
Growth Lead, Fintrail
“The real-time webhook took twenty minutes to wire into our signup form. Fake trial signups basically disappeared overnight.”
Daniel Cho
Founder, Loopstack
“We clean a 200K-row list before every campaign. What used to take our team a day now finishes before their coffee's cold.”
Meera Iyer
Lifecycle Marketing, Verdent
“Best false-positive rate of any verifier we tested — and we tested six.”
Tom Whitfield
CTO, Rally
Infrastructure
Handled like the sensitive data it is
SOC 2 Type II
Controls in progress — we treat verification data like the sensitive infrastructure it is.
GDPR-Compliant
No email content stored — only verification metadata. Data handling compliant with GDPR requirements.
Encrypted Everywhere
Data encrypted in transit (TLS 1.3) and at rest (AES-256).
Audit Logs
Full audit trails on all paid plans, with exportable logs.
Regional Residency
Data residency options in US, EU, and APAC for enterprise customers.
Frequently asked questions
What counts as a "disposable" or "temp" email?+
Addresses from services designed to be thrown away after one use — Mailinator, Guerrilla Mail, 10-minute-mail, and thousands of look-alike domains. OpenGuardian's disposable-domain list updates daily as new services appear.
Do you actually send a test email to verify an address?+
No. The SMTP check opens a connection to the receiving mail server and asks if the mailbox exists, without delivering a message — so the recipient never sees anything and your sender reputation isn't affected.
What's the difference between "risky" and "invalid"?+
Invalid means the address is malformed or the domain doesn't accept mail at all. Risky covers catch-all domains (which accept everything, so we can't confirm the specific mailbox), role-based addresses, and known spam-trap patterns.
Can I verify emails in real time at signup, not just in bulk?+
Yes — the real-time API/webhook returns a verdict in under 300ms, fast enough to gate a signup form before submission completes.
Will this slow down my signup form?+
No — the real-time check runs asynchronously against the same request cycle and returns well within a normal form-submit round trip; most integrations feel instant to the end user.
Is there a free plan?+
Yes — 1,000 free verifications with no card required, enough to test real signup traffic before committing.
Is OpenGuardian suitable for enterprise-scale sending?+
Yes — enterprise plans include private deployment, custom disposable-domain rules, SSO/RBAC, and dedicated support for teams verifying at very high volume.
Stop guessing which emails are real.
Run your first 1,000 verifications free — no card required.