Email Verification

SMTP-level verification that confirms every mailbox exists before you send.

Email Verification

Check Every Address

Validate one email before it enters a lead list, signup flow, or outbound workflow. The result shows status, SMTP verification, MX records, and reputation details in one product surface.

SMTP checkMX recordsDeliverability score
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BillionVerify single email verification result showing valid status, deliverable flag, reputation score, and SMTP check details

How It Works

Four automated checks run in sequence for every address.

1

Syntax Check

Validates format against RFC standards. Catches typos, invalid characters, and structural errors instantly.

2

Domain & MX Lookup

Confirms the domain exists and has valid mail server records configured to receive email.

3

SMTP Handshake

Opens a real connection to the receiving mail server. No test email sent, no spam risk.

4

Mailbox Confirmation

Verifies the specific address exists on the server and is deliverable before you send.

API Performance

API Performance

Fast enough for sign-up forms, reliable enough for production pipelines.

<200ms

Cached Latency

Previously seen addresses

1–3s

Full SMTP Check

Complete verification

99.9%

Accuracy

SMTP-level precision

99.99%

Uptime

Enterprise reliability

Frequently Asked Questions

1. How accurate is the verification?

BillionVerify achieves 99.9% accuracy through a real SMTP connection to each mailbox. The process covers syntax validation, MX record lookup, and direct SMTP handshake β€” confirming the specific address exists before you send.

2. How fast is the real-time API?

Previously seen addresses return in under 200ms from cache. A full SMTP verification completes in 1–3 seconds. Bulk jobs process up to 50,000 emails per hour.

3. Is my data secure?

All data is protected with 256-bit SSL encryption. BillionVerify is fully GDPR and CCPA compliant. Email addresses are automatically deleted after processing and never shared with third parties.

4. How does verification reduce bounces?

Verification catches invalid, disposable, and risky addresses before you hit send. Removing syntax errors, dead domains, and non-existent mailboxes upfront eliminates the hard bounces that damage sender reputation.

5. What does email verification cost?

Pay-as-you-go starts at $0.005 per email. Volume pricing goes as low as $0.001 per email for high-volume packages. A free tier provides 100 verifications daily with no credit card required.

6. Is there a free option?

Yes. You get 100 free verifications every day β€” no credit card, no signup required. The free tier includes all features: syntax checks, domain verification, SMTP validation, and disposable email detection.

Email Verification Service

Start Verifying Emails Today

SMTP-level verification with 99.9% accuracy. Real-time API and bulk processing included.

100 free verifications daily Β· 99.9% SMTP-level accuracy Β· No credit card required

99.9%
Accuracy
Real-time
API Speed
$0.00014
Per Email
100/day
Free Forever