001INPUT
Paste the address
Drop any email into the pill. Gmail, Outlook, custom domains, role aliases. Single address now, bulk CSV on signup.
Instant Bulk Verification
The Multiple Email Checker That Verifies a Whole List at Once.
Paste or upload a list, or a CSV, and verify every address at once with 99.99% accuracy on the same 9-point engine our paid API runs. No signup, no card.
Trusted by 500,000+ leading GTM teams of all sizes
From list to clean export
How the multiple email checker works
Three steps, no signup, no card on file. Paste or upload your list, watch the nine-check engine verify every address in parallel, then export the clean results.
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
Bulk email checking, without the tradeoffs
Most bulk email checkers quietly switch off the interesting checks once the list gets long. Ours runs the full nine-check pipeline the paid plans use on every address, 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 a multiple email checker really does
A multiple email checker takes a list, not a single address, and confirms every email on it is real, reachable, and safe to send to before you hit send. You have a CSV from a webinar, an export from your CRM, a scraped list a teammate handed you, and the one thing you do not have is confidence that the addresses are good. That is the gap this tool closes: paste the list or upload the CSV, and the bulk email checker verifies the whole thing at once instead of making you paste addresses one at a time.
The reason bulk matters is speed and parity. Checking a thousand addresses by hand is not realistic, so most people send to the raw list and let the inbox sort it out, which is exactly how a sender reputation gets wrecked. Verifox verifies every address in parallel at roughly ten thousand emails per minute, and crucially it runs the same nine-check engine on the ten-thousandth address as it does on the first. Syntax, MX records, a live SMTP handshake, disposable-domain filtering, role-address detection, and an AI-confidence pass on catch-all domains all run on every row. That last one is where a single-address check and a serious bulk run pull ahead of the cheap tools, because catch-all domains are where silent bounces hide on a B2B list.
When the run finishes you get the list back tagged valid, invalid, or risky, with a confidence score on each, ready to export as a clean CSV. Suppress everything that is not valid, import the rest, and your next campaign goes out to a list that actually delivers. Need the same engine pointed at building the list in the first place? The bulk email finder finds and verifies addresses at scale. Wiring it into a sequencer, a CRM, or an AI agent? The same verification engine is available through the bulk REST API and a native MCP server, with pay-as-you-go pricing localized to 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
Checking lists, answered
The questions we get from teams that land here to check multiple emails at once, with the real numbers, real limits, and real opinions behind our verification stack.
How do I upload a list of emails to check?
Two ways. Paste a column of addresses straight into the box above (one per line, or comma-separated), or upload a CSV and we map the email column for you. Either way the multiple email checker runs the full nine-check engine over every row in parallel, then hands you the clean list back to export.
For lists that live in a CRM or a script, skip the upload entirely and POST them to the bulk email API. Same engine, same accuracy, results streamed back as JSON. Both paths are available from the free tier up.
Is the multiple email checker actually free?
Yes. You can check 4 emails per day from this page without an account. No card, no signup.
Create a free account and you get 1,000 checks on the spot, or 2,500 if your signup email is a work address, which is enough to clean a whole list outright. After that, credits are pay-as-you-go and never expire on any paid plan, with volume pricing shown for your region.
How many emails can I check at once?
There is no hard cap on a single batch. Lists of a few hundred finish in seconds; lists of tens of thousands stream back as the engine works through them. Bulk processing runs at roughly 10,000 emails per minute on the standard tier because every address is verified in parallel, not one after another.
The only practical limit is your credit balance, and credits are pay-as-you-go and never expire. Run a list of 50 today and a list of 50,000 next week off the same balance.
What does this bulk email checker actually check?
Nine checks run in parallel on every address in your list:
- 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
The catch-all resolution is the one most bulk email checkers skip, and it's where 20 to 40 % of B2B email lists actually fail. If you only need to check one email at a time, the checker runs the very same engine.
How accurate is the bulk email verification?
Same engine as the paid plans. 99.99 % accuracy on a 1,000-address benchmark list, including catch-all domains.
The free tier doesn't trade accuracy for the price tag. It caps volume only. Every check the paid Email Verification API runs on a list is the same check the bulk email checker on this page runs.
What results do I get back, and can I export them?
Every address comes back tagged valid, invalid, or risky, with a confidence score from 0 to 100 and the per-check breakdown behind it. Disposable, role-based, and catch-all addresses are flagged so you can decide what to keep.
Export the cleaned list as a CSV, or pull the same results as JSON over the API. Most teams suppress everything that is not valid before importing the rest into their sender, which is exactly what an email bounce checker would catch on send, only earlier.
Do you store the emails I check?
No. Lists are processed in memory and discarded the moment the bulk check completes. Nothing logged, nothing retained, nothing sold.
We're SOC 2 Type II compliant with the full Trust Center report on request. Read the privacy policy for the byte-by-byte breakdown of what we touch and what we don't.
What's the difference between a multiple email checker and a verifier?
In practice, nothing. A multiple email checker, a bulk email verifier, and a bulk email validator all do the same job: take a list and confirm every address is real, reachable, and safe to send to. Verifox runs the identical nine-check engine whatever you call it.
If you prefer the validator phrasing, the free email validator runs the same engine on bulk lists, and the same verification engine powers every plan, free or paid.
How fast is the bulk API and what's the SLA?
Bulk processing runs at roughly 10,000 emails per minute on the standard tier. A single address is around 380 ms, sub-50 ms for cached results.
SLA is 99.9 % uptime on Starter, 99.99 % with an annual Volume contract. Full real-time uptime + incident history at status.verifox.ai. Implementation details in the API docs.
Can I add bulk email checking 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 and batch email checking into signup forms, CRMs, or any tool that speaks REST. HubSpot, Salesforce, Zapier, Klaviyo, Mailchimp, and Brevo all connect out of the box.
Verifox also ships native MCP server support so AI agents (Claude, Cursor, custom LLM apps) can check whole lists without glue code. Drop the MCP URL into your agent config and the tools are wired.