001INPUT
Paste the address
Drop any email into the pill. Gmail, Outlook, custom domains, role aliases. Single address now, bulk CSV on signup.
Every Send Is a Chain
The Email Link Checker That Tests Your Weakest Link First.
Confirm any address still links to a real mailbox in 2 seconds, then jump straight to the html email checker and content tests for the rest of the chain. No signup, no card.
Trusted by 500,000+ leading GTM teams of all sizes
From paste to verdict
How the email link checker works
Three steps, no signup, no card on file. Paste the recipient address, let the nine-check engine test the mailbox link, 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.
- 01
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.
- 02
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.
- 03
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.
- 04
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.
- 05
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.
- 06
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.
- 07
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.
- 08
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.
- 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. Specific numbers, specific tools they switched from, and a verified email address 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
Why this one
Link checking that starts where bounces start
Most link checkers start at your HTML and never ask whether the mailbox exists. Ours tests the recipient link with the full nine-check pipeline the paid plans run, 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 link checker and email html tester should cover
Search for an email link checker and you will find three different products wearing the same name. Some crawl the hyperlinks inside your HTML body and report broken hrefs. Some are really an email html tester, rendering your template across Outlook, Gmail, and Apple Mail to catch markup that collapses. And some test the link people forget is a link at all: whether the recipient address still connects to a live mailbox. Every send depends on all three, and they fail in a fixed order. The mailbox fails first, the sender domain second, the content last.
That order is why the tool on this page starts with the address. A hard bounce ends the conversation before your design or your links ever load, and mailbox providers punish bounce rates faster than any content mistake. Between 20 and 40% of B2B lists fail at catch-all domains specifically, the check most free tools skip. Verifox runs the full nine-point email verification engine on every paste: syntax, MX, SMTP handshake, catch-all scoring, disposable and role detection, domain age, and authentication. Same engine as the free email checker, measured at 99.99% accuracy on a 1,000-address benchmark.
Then work down the chain. The html email checker handles template and rendering faults, the spam content checker flags the link patterns filters resolve and score, and the email blacklist check tells you if your own domain is the broken link. Watch the whole pipeline with the deliverability tester, or automate every step through the REST API with pay-as-you-go credits priced for your region on the pricing page.
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.
Common questions
Email link checking, answered
What teams ask before a send: which link breaks first, what blacklisted links cost you, where duplicate addresses hide, and what this checker does and does not test.
What does an email link checker actually test?
Three links sit between your draft and a reply: the recipient address, your sender domain, and the hyperlinks inside the HTML body. This page tests the first and most fragile one. Paste an address and the nine-check verification engine confirms it connects to a real, deliverable mailbox: syntax, MX records, SMTP handshake, catch-all and disposable detection, and more.
The other two links have their own tools. Test your sending domain with the email blacklist check and your message body with the spam content checker.
Is the email link checker free to use?
Yes. You get 4 checks per day on this page with no account and no card.
Sign up free and that becomes 1,000 verification credits immediately, or 2,500 if you register with a work address. Credits are pay-as-you-go and never expire, and larger packs carry volume pricing shown for your region on the pricing page.
Can I check the links inside an HTML email before sending?
You should, and the order matters. Run the address check on this page first, because a dead mailbox ends the send before anyone can click anything. Then move to the body: the html email checker covers template and markup problems, and the spam content checker flags the wording and link patterns that filters punish.
That sequence mirrors how mailbox providers actually evaluate you: recipient first, sender second, content last.
How do broken or blacklisted links hurt deliverability?
Spam filters resolve the domains behind every hyperlink in your message. One link pointing at a blocklisted shortener or a flagged tracking domain can push an otherwise clean email to spam. Broken links do quieter damage: recipients who click into a 404 stop clicking, and falling engagement drags your future placement down.
Audit your own domain with the blacklist check and watch overall inbox placement with the email deliverability tester.
Why check the email address before the links inside the message?
Because bounces happen first. If the mailbox does not exist, your carefully tested HTML never renders and every body link is dead weight. Mailbox providers also score bounce rates harshly: a burst of hard bounces marks you as a careless sender before content scanning even begins.
The risk is bigger than most teams assume. Between 20 and 40% of B2B email lists fail at catch-all domains, the exact case the catch all email checker scores instead of shrugging at.
Does this work as a duplicate email checker for lists?
Yes. Paste or upload a list and duplicates are collapsed before verification runs, so each unique address is checked once and you never spend two credits on the same contact. Bulk jobs process at roughly 10,000 emails per minute on the standard tier.
For pasting batches straight from a spreadsheet, the multiple email checker is built for exactly that flow, and the free email validator handles CSV upload from the free tier up.
How accurate is the mailbox check behind this tool?
99.99% accuracy on a 1,000-address benchmark list, including the catch-all domains most free tools skip. It is the same engine our paid verification service runs; the free tier caps volume, never depth.
Speed holds up too: median latency is about 380 ms per address and under 50 ms for cached results, which is why the verdict on this page lands in about two seconds.
Do you store the emails I check on this page?
No. Every address is processed in memory and discarded the moment the verdict returns. Nothing is stored, logged, or sold, and there is no shadow list quietly building behind the free tool.
Verifox is SOC 2 Type II compliant, and the privacy policy spells out exactly what we touch and for how long. Short version: your list stays yours.
Can I automate email link checking from my own app or AI agent?
Yes. The REST API exposes the full nine-check verdict for single addresses and bulk jobs, so you can gate signup forms, clean CRM imports, or verify before every campaign without opening this page.
AI agents get a native MCP server: point Claude, Cursor, or a custom LLM app at the MCP URL and the verification tools are wired with no glue code. Forms on your own site can use the FoxGuard widget instead.
What is an email html tester and when do I need one?
An email html tester renders your template the way real clients do and flags markup that breaks: unclosed tags, images that will not load, layouts that collapse on mobile. You need one before any campaign where the design matters, because Outlook, Gmail, and Apple Mail each render HTML differently.
Run yours through the email template checker, and confirm your authentication records separately with the DMARC, DKIM and SPF check. Live uptime for all tools sits at status.verifox.ai.
Before your next send
Test every link in your list, on us
Create a free account and get 1,000 verification credits, or 2,500 if you sign up with a work address. No card required, and credits never expire. Bulk runs at roughly 10,000 emails a minute, so most campaign lists finish before your coffee does.