001INPUT
Paste the address
Drop any email into the pill. Gmail, Outlook, custom domains, role aliases. Single address now, bulk CSV on signup.
Verify Any Email Address
The Email Verifier Built on a 9-Check Engine. Verdict in 2 Seconds.
Verify any email address with 99.99% accuracy, single or in bulk, on the same 9-point email validation engine our paid API runs. No signup, no card.
Trusted by 500,000+ leading GTM teams of all sizes
Paste. Verify. Send.
How the email verifier works
Three steps, no signup, no card on file. Paste any address, watch the nine-check engine verify it, read the verdict in two seconds.
002ENGINE
Run the 9-check engine
Nine checks fire in parallel. Syntax, DNS, SMTP, catch-all, disposable, role, age, auth, mailbox state. Verdict in about two seconds.
003VERDICT
Verdict in 2 seconds
Valid, invalid, or risky. Plus a confidence score, the per-check breakdown, and a recommended retry policy. Read on the page or via API.
The 9-point engine
Nine checks. One verdict.
The same nine-check engine our paid email verification API runs. Every email, every verification, every time.
- FormatCheck 01 / 09
Syntax
Every address runs a full RFC 5321 and RFC 5322 compliance pass before a single network call goes out. The engine catches what visual scanning misses, the double dot in
alice@verifox..ai, the trailing period, the IDN homograph that looks valid but resolves to a different domain.Bundled typo suggestions let your form offer “did you mean alice@gmail.com?” instead of rejecting silently.
- InfrastructureCheck 02 / 09
Domain & MX
Once syntax passes, the engine resolves the domain. We confirm the DNS records exist, fetch the MX record priority list in order, and verify at least one mail-exchange server is actively accepting connections right now.
Misspelled domains like
gmial.com, expired domains, and parked-for-sale domains all fail this gate before the engine wastes a single SMTP roundtrip.
- Live ProbeCheck 03 / 09
SMTP handshake
The engine opens a TCP connection on port 25, performs the EHLO handshake, then negotiates
MAIL FROMandRCPT TO. Every server response code (220, 250, 550, 552) is parsed deterministically against the IANA enhanced-status registry.This is the moment a mailbox proves it actually exists. No third-party guesses, no statistical heuristics, just the receiving server's own answer.
- RiskCheck 04 / 09
Catch-all detection
Some domains accept every email regardless of whether the mailbox exists, a setup known as a catch-all configuration. The engine sends a deterministic probe to a deliberately fake address (
zzz9k7q@domain.com); if the server returns the same 250 OK it returned for the real address, the domain is catch-all.The verdict isn't dropped, it's flagged RISKY so you know the deliverability signal is degraded.
- HygieneCheck 05 / 09
Disposable
The engine maintains a curated registry of 10,247 disposable email providers, including Mailinator, Guerrilla Mail, 10MinuteMail, Tempmail, and the long tail of regional clones.
Any address matching the blocklist is flagged INVALID. Deliverability to a mailbox that exists for 10 minutes and is never checked is functionally zero, regardless of whether the SMTP handshake passes.
- ClassificationCheck 06 / 09
Role address
info@,support@,no-reply@,admin@,hello@,billing@,contact@. These are shared inboxes, not individuals.The engine extracts the local-part of every address, matches it against the known role-prefix registry, and tags the result with a reduced engagement score.
You don't drop them automatically. The verdict tells you they're roles so you can decide whether they belong in your outbound.
- RiskCheck 07 / 09
Domain age
Fresh-spam domains registered hours ago are the single biggest source of inbound abuse. The engine queries WHOIS and RDAP for every unique domain, extracts the registration date, and flags anything under 30 days old with a “fresh” warning.
Domains aged 5+ years pick up a corresponding trust signal. The same heuristic spam filters have been using since the early 2000s, ported into the verdict.
- InfrastructureCheck 08 / 09
Email authentication
SPF, DKIM, and DMARC together prove the sender is authorised to send from that domain.
The engine reads each policy via DNS, validates SPF includes recursively, scans six common DKIM selectors for a published key, and confirms DMARC alignment with the
From:header.A failing DMARC policy means the sender can be spoofed, so the verdict warns you before you reply.
- VerdictCheck 09 / 09
Mailbox state
Beyond “exists vs doesn't exist”, the engine extracts the precise mailbox state from the SMTP server's response. Full inbox (552 / 522 quota), disabled mailbox (550 5.1.1), out-of-office autoresponder, frozen account.
Each state maps to a specific retry policy. Full inbox retries in 6 hours. Disabled drops permanently. The verdict tells you which bucket the bounce belongs in so your retry logic doesn't waste cycles.
How we stack up
Verifox vs the alternatives
Same nine-check pipeline, the highest published accuracy, credits that never expire, and an MCP server no competitor offers. Head-to-head with the two providers our buyers shortlist.
| Feature | Verifox | NeverBounce | ZeroBounce |
|---|---|---|---|
| Published accuracy claim | 99.99% | 99.0% | 99.6% |
| Credits expire | Never | Yes | Never |
| Free credits on signup | 1,000–2,500 / one-time | 1,000 / monthly | 100 / monthly |
| Verify without signup | |||
| Catch-all resolution | AI confidence | Flagged only | AI scoring |
| Real-time API | |||
| Bulk CSV upload | |||
| MCP server for AI agents | |||
| SOC 2 + GDPR + CCPA |
What teams are saying
Built for the teams that ship outbound
Growth leads, marketers, and engineers running real campaigns on real lists, with a verified email on every byline.
90% lower bill, 0.4% bounces
We were paying ZeroBounce a four-figure monthly bill and still landing 3% bounces on cold campaigns. Switched the pipeline to Verifox, dropped to 0.4% bounces, and cut the bill by more than 90%.
Thomas G.GTM Lead, Stripe
Catch-all finally has a verdict
Other tools flag 30% of our B2B list as 'risky catch-all' and leave the call to us. Verifox returns a real verdict on those addresses, with a confidence score. We send more, we send safer.
Brittany K.GTM Lead, HubSpot
Reputation rebuilt in 6 weeks
We had a Gmail spam-folder problem after a bad list import. Verifox cleaned the list and the warmup ran on the same engine. Back in primary inbox in six weeks. One vendor, half the cost.
Dale M.GTM Lead, Slack
0.7% bounce on 50k
Ran a 50,000-address outbound list through Verifox before our quarterly campaign. Bounces landed at 0.7%, sender reputation didn't move, replies were up 22% over last quarter.
Erica K.GTM Lead, Discord
MCP in 10 minutes
Their MCP server let me wire email verification directly into our internal Claude agent in about ten minutes. Zero glue code. No other vendor in this space has thought about that workflow.
Greg L.GTM Lead, OpenAI
10k/min held under 400ms
Tested Verifox at 10,000 verifications per minute on a Tuesday morning. Latency held under 400ms median, no soft failures, no rate-limit walls. The vendor we benched throttled at 2,000/min.
Rini V.Product Manager, Vercel
Hygiene that doesn't break pipeline
Our SDRs were enriching from three tools and 14% of the emails were invalid before they hit the sequencer. Verifox sits in the pipeline now and the team stopped seeing 'undeliverable' replies the next week.
Jonathan A.GTM Lead, MongoDB
Bulk that actually ships
Bulk upload, sorted CSV back in twenty minutes, plug into our growth stack. The half-day list-hygiene project per cohort turned into something the marketing intern runs on autopilot.
Emma F.GTM Lead, Linear
Scores you can act on
Verifox returns a 0-100 confidence score per address, not just a label. We thresholded at 75 for the cold sequencer, 60 for nurture, and our deliverability team finally has a knob they can tune.
David H.GTM Lead, Snowflake
90% lower bill, 0.4% bounces
We were paying ZeroBounce a four-figure monthly bill and still landing 3% bounces on cold campaigns. Switched the pipeline to Verifox, dropped to 0.4% bounces, and cut the bill by more than 90%.
Thomas G.GTM Lead, Stripe
Reputation rebuilt in 6 weeks
We had a Gmail spam-folder problem after a bad list import. Verifox cleaned the list and the warmup ran on the same engine. Back in primary inbox in six weeks. One vendor, half the cost.
Dale M.GTM Lead, Slack
MCP in 10 minutes
Their MCP server let me wire email verification directly into our internal Claude agent in about ten minutes. Zero glue code. No other vendor in this space has thought about that workflow.
Greg L.GTM Lead, OpenAI
Hygiene that doesn't break pipeline
Our SDRs were enriching from three tools and 14% of the emails were invalid before they hit the sequencer. Verifox sits in the pipeline now and the team stopped seeing 'undeliverable' replies the next week.
Jonathan A.GTM Lead, MongoDB
Scores you can act on
Verifox returns a 0-100 confidence score per address, not just a label. We thresholded at 75 for the cold sequencer, 60 for nurture, and our deliverability team finally has a knob they can tune.
David H.GTM Lead, Snowflake
Catch-all finally has a verdict
Other tools flag 30% of our B2B list as 'risky catch-all' and leave the call to us. Verifox returns a real verdict on those addresses, with a confidence score. We send more, we send safer.
Brittany K.GTM Lead, HubSpot
0.7% bounce on 50k
Ran a 50,000-address outbound list through Verifox before our quarterly campaign. Bounces landed at 0.7%, sender reputation didn't move, replies were up 22% over last quarter.
Erica K.GTM Lead, Discord
10k/min held under 400ms
Tested Verifox at 10,000 verifications per minute on a Tuesday morning. Latency held under 400ms median, no soft failures, no rate-limit walls. The vendor we benched throttled at 2,000/min.
Rini V.Product Manager, Vercel
Bulk that actually ships
Bulk upload, sorted CSV back in twenty minutes, plug into our growth stack. The half-day list-hygiene project per cohort turned into something the marketing intern runs on autopilot.
Emma F.GTM Lead, Linear
90% lower bill, 0.4% bounces
We were paying ZeroBounce a four-figure monthly bill and still landing 3% bounces on cold campaigns. Switched the pipeline to Verifox, dropped to 0.4% bounces, and cut the bill by more than 90%.
Thomas G.GTM Lead, Stripe
0.7% bounce on 50k
Ran a 50,000-address outbound list through Verifox before our quarterly campaign. Bounces landed at 0.7%, sender reputation didn't move, replies were up 22% over last quarter.
Erica K.GTM Lead, Discord
Hygiene that doesn't break pipeline
Our SDRs were enriching from three tools and 14% of the emails were invalid before they hit the sequencer. Verifox sits in the pipeline now and the team stopped seeing 'undeliverable' replies the next week.
Jonathan A.GTM Lead, MongoDB
Catch-all finally has a verdict
Other tools flag 30% of our B2B list as 'risky catch-all' and leave the call to us. Verifox returns a real verdict on those addresses, with a confidence score. We send more, we send safer.
Brittany K.GTM Lead, HubSpot
MCP in 10 minutes
Their MCP server let me wire email verification directly into our internal Claude agent in about ten minutes. Zero glue code. No other vendor in this space has thought about that workflow.
Greg L.GTM Lead, OpenAI
Bulk that actually ships
Bulk upload, sorted CSV back in twenty minutes, plug into our growth stack. The half-day list-hygiene project per cohort turned into something the marketing intern runs on autopilot.
Emma F.GTM Lead, Linear
Reputation rebuilt in 6 weeks
We had a Gmail spam-folder problem after a bad list import. Verifox cleaned the list and the warmup ran on the same engine. Back in primary inbox in six weeks. One vendor, half the cost.
Dale M.GTM Lead, Slack
10k/min held under 400ms
Tested Verifox at 10,000 verifications per minute on a Tuesday morning. Latency held under 400ms median, no soft failures, no rate-limit walls. The vendor we benched throttled at 2,000/min.
Rini V.Product Manager, Vercel
Scores you can act on
Verifox returns a 0-100 confidence score per address, not just a label. We thresholded at 75 for the cold sequencer, 60 for nurture, and our deliverability team finally has a knob they can tune.
David H.GTM Lead, Snowflake
Built for accuracy
Email verification, without the tradeoffs
Most free email verifiers quietly switch off the interesting checks. Ours runs the full nine-check pipeline the paid plans use, capped only on volume.
Accuracy
99.99%accuracy
The same nine-check engine
The free tier runs the full nine-check pipeline from our email verification API, capped on volume and never on accuracy.
Friction
0signups to begin
No signup to start
Verify your first emails right here with no signup at all. Create a free account when you go past four checks a day.
Coverage
10kemails / minute
API and bulk, included
Your free plan unlocks the very same REST API, CSV upload, and bulk parallel processing that the paid plans run on.
Privacy
SOC 2GDPR · CCPA
Emails are never stored
Addresses are processed in memory and dropped on response, nothing stored and nothing sold. Read the privacy policy.
The honest version
What an email verifier actually does
An email verifier answers one question: if you sent a message to this address right now, would it land? Matching the text against RFC rules is the easy part, and it is where most free tools stop. Verifox goes the rest of the way. It looks up the domain's MX records, opens a real SMTP conversation with the receiving server, and asks it to accept the mailbox exactly the way a sending server would, then disconnects before any message exists. Nothing is sent, nobody gets pinged, and the verdict is grounded in what the mail server actually said. The full method, all nine checks of it, is documented on the email verification service page.
The hard cases are catch-all domains: servers configured to accept mail for any address, whether the mailbox exists or not. A plain handshake calls every one of them deliverable, which is how lists that “verified clean” still bounce. And because 20 to 40% of B2B email lists sit behind catch-all domains, this is not an edge case; it is the main event. Verifox runs an AI-confidence pass on every catch-all hit, weighing domain age, authentication records, and naming patterns to score how likely that specific mailbox is real. That layer is the difference between a verdict and a guess.
One address or two hundred thousand, the pipeline is identical. Paste a single email above for a free check, upload a CSV from the dashboard, or wire the REST API into your signup flow; bulk jobs move roughly 10,000 emails a minute on the standard tier. If you landed here searching for a validator, the free email validator is this same engine under that name. Credits are pay-as-you-go, never expire, and volume pricing is localized to your region.
Trust & compliance
Enterprise-grade security and scale
Every layer of the stack carries a third-party attestation, so you can ship into regulated industries without rebuilding your compliance posture.
SOC 2 Type II
Independently audited to the SOC 2 Type II standard.
GDPR
Built for the EU with full GDPR data-subject rights.
CCPA
California opt-out, do-not-sell, plus DSAR handling.
ISO 27001
Information security held to the ISO 27001 standard.
ISO 42001
AI governance aligned to the new ISO 42001 standard.
Free resource
The 9-Point Email Verification Checklist
A 17-page field guide: every verification check explained, the five hidden mistakes that kill deliverability, and a one-page audit you can run this afternoon. Free PDF.
Common questions
Email verification, answered
The questions we get from teams that land here to verify an email address, with the real numbers, real limits, and real opinions behind our verification stack.
Can I verify an email address without sending an email?
Yes, and that is the entire job of an email verifier. Verifox opens a live SMTP conversation with the domain's mail server, asks it to accept the address exactly the way a real sending server would, reads the response, and disconnects before any message content moves. The mailbox owner never sees a thing.
The whole exchange takes about 380 ms at the median. The full method, check by check, is documented on the email verification service page.
Is the email verifier free?
Yes, with honest caps. The widget at the top of this page runs 4 verifications a day with no account and no card.
A free signup adds 1,000 credits immediately, or 2,500 when you register with a work address. Beyond that, credits are pay-as-you-go, never expire, and carry volume pricing localized to your region.
What does the email verifier check before calling an address valid?
Nine checks, all running in parallel on every address:
- Syntax + format validation (RFC 5321 / 5322)
- Domain existence and MX record presence
- SMTP handshake and mailbox-exists ping
- Disposable-domain match
- Role-address detection
- Catch-all domain detection
- AI-confidence pass on catch-all addresses
- Domain age signal
- SPF / DKIM / DMARC email-authentication check
Only when an address clears the stack does it come back valid. If you just want a quick one-off look at a single address, the free email checker runs this exact engine behind a simpler page.
What does a risky verdict from the email verifier mean?
Risky means the mailbox could not be confirmed or ruled out with certainty, so we hand you the evidence instead of a coin flip. The usual causes: a catch-all domain that accepts every address during the handshake, a role inbox like info@ or sales@, a domain registered days ago, or missing SPF, DKIM, and DMARC records.
Every risky result ships with a confidence score and the per-check breakdown, so you can pick your own send-or-suppress threshold instead of inheriting ours.
How do I verify a catch-all email address?
You need more than an SMTP handshake, because a catch-all server says yes to every address, real or invented. Verifox layers an AI-confidence pass on top: it weighs the domain's age, authentication posture, and naming patterns to score how likely that specific mailbox actually exists.
That layer is the one most free tools skip, and it matters: 20 to 40% of B2B email lists sit behind catch-all domains. Catch-all resolution is where this verifier earns its accuracy number.
How accurate is the email verifier?
99.99% on our 1,000-address benchmark list, measured in-house and including the catch-all cases most tools mark unknown. The engine has verified 2.1B+ emails to date.
Free and paid run the identical pipeline. The free tier caps how many addresses you can verify, never how deeply each one gets checked, so the verdict on this page matches what the API returns for the same address.
What file formats does the bulk email verifier accept?
CSV upload from the dashboard, or stream addresses straight through the REST API for anything programmatic. Bulk jobs process roughly 10,000 emails per minute on the standard tier, and every address in the file gets the full nine-check treatment with a per-address verdict and confidence score.
Your free signup credits cover small lists outright. For bigger ones, credit packs are pay-as-you-go and never expire.
Do you keep the addresses I verify?
No. Each address is verified in memory and discarded the instant the verdict returns. We never store, log, or sell what you paste here, on the free tier or any paid one.
Verifox is SOC 2 Type II certified, and the privacy policy spells out exactly what we touch and for how long. Short version: the address lives as long as the verification does.
What's the difference between an email verifier and an email validator?
In practice, nothing. People say “verify email address” and “validate email address” to mean the same job: confirm an address is real, reachable, and safe to send to. Verifox runs the identical nine-check engine either way.
If you prefer the validator phrasing, the free email validator is the same tool under a different name. Both share the same accuracy, the same verification engine, and the same free tier.
Can I add email verification to my own app or AI agent?
Yes. The REST API reference documents the inbound and outbound shapes for every endpoint, so you can drop real-time email verification into signup forms, CRMs, or any tool that speaks REST. At a 380 ms median per verification it sits comfortably inside a form submit, and the SLA is 99.9% uptime on Starter, 99.99% on an annual Volume contract, with live status at status.verifox.ai.
Verifox also ships native MCP server support so AI agents (Claude, Cursor, custom LLM apps) can verify addresses without glue code. Drop the MCP URL into your agent config and the tools are wired. HubSpot, Salesforce, Zapier, Klaviyo, Mailchimp, and Brevo connect out of the box as well.