SF Email VerifierSF Email Verifier
/// email verifier

Email verifier

An email checker that doesn't give up on Gmail and Yahoo.

Verify a single address in real time or clean a whole list in bulk. 20 free credits every day, and you only pay for results you can actually act on.

Start free, no card needed

Try a Gmail or Yahoo address, that's where most verifiers quietly fail.

sf email verifier · live demo
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try:

> awaiting input…

> runs 8 checks: syntax, mx, smtp, catch-all, role, disposable, free-provider, spam-trap

> typical response: 800–1500ms

/// how it works

How verification works

Four checks, one credit, an answer you can trust.

/// 01
Syntax and MX check

Confirms the address is well-formed and that the domain has a working mail server before spending a credit.

/// 02
SMTP handshake

Connects to the real mail server and asks whether the specific mailbox accepts mail, the same step most checkers stop at.

/// 03
Provider-specific resolution

For Gmail and Yahoo domains, runs deeper checks instead of defaulting to a generic catch-all label.

/// 04
Disposable & role detection

Flags throwaway domains and generic addresses like info@ or support@ so you can decide how to treat them.

/// why this matters

Why this matters

Catch-all domains break basic SMTP checks.

A mail server can return the same accept signal for a real mailbox and a made-up one, that's true on any catch-all domain, but it's especially common on Yahoo tenants and Gmail Workspace setups. A verifier that doesn't account for this either rubber-stamps junk as valid or discards real contacts as catch-all.

/// what we do differently

What we do differently

  • Provider-aware logic for Gmail and Yahoo instead of one generic SMTP probe
  • Clear status per address: valid, invalid, risky, or disposable, never a vague “unknown” dump
  • Unknown and greylisted results are free, so ambiguity never costs you a credit
/// bulk

Bulk email verifier

Clean a list of 10 or 100,000 the same way.

  • CSV or TXT, up to 1M rows per job
  • Jobs auto-delete after 7 days for privacy
  • Only actionable results use a credit
results.csv
email,status
jane@Yahoo.com,valid
sales@bigco.com,valid
asdkj923@mailinator.com,disposable
typo@gmali.com,invalid
/// api

Verification API

Verify at signup, not after the bounce.

Call the same engine behind the dashboard from your own signup form, CRM, or outreach tool. JSON in, a clear status out.

curl
curl https://api.sfemailverifier.com/v1/verify \
  -H "Authorization: Bearer YOUR_KEY" \
  -d email=jane@Yahoo.com
response
{
  "email": "jane@Yahoo.com",
  "status": "valid",
  "disposable": false,
  "credit_used": true
}
/// questions

Email verifier FAQ

What's the difference between an email checker and an email validator?+

People use the terms interchangeably. We run both layers: syntax/format validation (does it look like a real address) and live deliverability verification (does the mailbox actually exist and accept mail).

Do unknown or catch-all results cost a credit?+

Unknown and greylisted results are always free. Catch-all results cost a credit because they're actionable, many businesses choose to send to catch-all domains anyway.

Can I verify a list in bulk?+

Yes, upload a CSV with up to 1M rows. We process in the background and you get a result CSV you can download. Per-row cost is the same as single checks.

Is there a verification API?+

Yes. Every plan, including the free 20-credit daily tier, includes the same JSON API the dashboard uses. Bearer-token auth, JSON responses.

Start verifying for free, right now.

20 credits every day, forever. No credit card, no trial clock.

Create your free accountSee pricing