Now serving 2.4M verifications today·v3.2 just shipped

Email validation,
at factory prices.

The same industry-grade verification the big players use — at 30× less.98.42% accuracy. 50,000 daily credits. $49 a month. No asterisks.

No credit card required·Free 1,000-credit trial·Cancel anytime
$curl -X POST https://api.mailboxverifier.com/v1/validate -H "Authorization: Bearer ev_live_xxxxx"Copy
app.mailboxverifier.com / verify
⌘K
Single Verify
founder@stripe.com
SMTP · MX · Syntax1 credit / verify
1Syntax
2MX records
3SMTP handshake
Result
Verified accuracy
98.42%
Median response
180ms
Daily credits
50,000
Cheaper than competitors
30×
someone@stripe.comvalidsomeone@hubspot.comvalidsomeone@figma.comcatchallsomeone@acme-corp.iovalidsomeone@fake-xyz.ruinvalidsomeone@vercel.comvalidsomeone@shopify.comvalidsomeone@ghost.cominvalidsomeone@linear.appvalidsomeone@openai.comcatchallsomeone@notion.sovalidsomeone@nope.bizzinvalidsomeone@stripe.comvalidsomeone@hubspot.comvalidsomeone@figma.comcatchallsomeone@acme-corp.iovalidsomeone@fake-xyz.ruinvalidsomeone@vercel.comvalidsomeone@shopify.comvalidsomeone@ghost.cominvalidsomeone@linear.appvalidsomeone@openai.comcatchallsomeone@notion.sovalidsomeone@nope.bizzinvalidsomeone@stripe.comvalidsomeone@hubspot.comvalidsomeone@figma.comcatchallsomeone@acme-corp.iovalidsomeone@fake-xyz.ruinvalidsomeone@vercel.comvalidsomeone@shopify.comvalidsomeone@ghost.cominvalidsomeone@linear.appvalidsomeone@openai.comcatchallsomeone@notion.sovalidsomeone@nope.bizzinvalidsomeone@stripe.comvalidsomeone@hubspot.comvalidsomeone@figma.comcatchallsomeone@acme-corp.iovalidsomeone@fake-xyz.ruinvalidsomeone@vercel.comvalidsomeone@shopify.comvalidsomeone@ghost.cominvalidsomeone@linear.appvalidsomeone@openai.comcatchallsomeone@notion.sovalidsomeone@nope.bizzinvalid

Trusted by teams at

Strata
Mercato
Halcyon
Northwind
Lumen & Co
Quanta
The product

Six things. All of them done.

We didn't build a 47-feature platform. We built the email validator we wished existed when we were paying $499/mo to send 100k emails.

01

Single verify

Paste one email. Get an instant valid / invalid / catch-all verdict in under 200ms — with SMTP, MX and syntax check.

02

Bulk CSV upload

Drag in a list of 1,000 or 1,000,000. We process it in parallel, deduplicate, and stream results you can export.

03
?

Catch-all detection

MailboxVerifier doesn't just stop at valid / invalid. It surfaces the catch-all addresses that quietly wreck your sender reputation.

04

Real-time dashboard

A live history of every job, every result, every status. Filter, sort, re-verify, export — your data is never locked away.

05

Built for cold emailers

Drop your bounce rate from 8% to under 1%. Protect your domain reputation. Stop paying mailbox providers to reject you.

06

Honest, plain pricing

$49 a month. 50,000 daily credits. That's the whole pricing page. No seat fees. No usage tiers. No enterprise upsell.

How it works

Three steps.
Zero learning curve.

You don't need to read a manual. You don't need a sales call. You sign up, you verify, you ship.

Average verify: 180ms
Step 01

Paste or upload

Drop a single email into the verify box — or upload a CSV with up to a million rows. We auto-detect the column.

Drop file
leads-q3.csv
12,481 rows · 2.1MB
UTF-8auto-detect column
Step 02

We run the checks

Syntax, MX records, SMTP handshake, role-account and disposable heuristics — run in parallel across our infrastructure.

Syntax check100%
MX records100%
SMTP handshake78%
Catch-all probe42%
14,328 / 18,200 processed
Step 03

Get clean results

Each row comes back tagged valid, invalid, or catch-all. Filter, sort, and export to CSV in two clicks.

Email
Status
Code
amy@stripe.com
valid
ok
mark@nope.invalid
invalid
ko
ops@openai.com
catchall
mb
liz@figma.com
valid
ok
By the numbers

Numbers, not adjectives.

We measure, we publish, we don't round up. Here's exactly what the platform is doing right now.

Verified accuracy · live measurement
0.00
%
Out of every 100,000 emails we verify, 98,420 land in the right bucket. The remaining 1,580 are the ones no validator on earth can call with certainty — catch-all servers, grey-listed inboxes, fresh domains.
0M+
Verifications run today
Live count, resets at 00:00 UTC
0ms
Median response time
p95 under 320ms across regions
0×
Cheaper than competitors
On a like-for-like credit basis
Methodology

Where 98.42% actually comes from.

Every release is scored against a labelled corpus of 100,000+ addresses. Ground truth is established by manual SMTP probes. We retest weekly and publish every number.

Precision
99.10%
Recall
97.84%
F1
98.46%
False +
0.84%
False −
1.31%
Cohort
100k
Honest comparison

Same engine. Wildly different invoice.

The other guys built email validation in 2014 and never re-priced it. We re-built the stack from scratch and decided to pass the savings to you.

Capability
MailboxVerifier
this
Industry avg.
Daily credits
50,000
1,000 – 5,000
Monthly price
$49
$249 – $499
Per-credit cost
$0.00003
$0.0010+
Cost multiplier
30× – 100×
Catch-all detection
Bulk CSV (1M rows)
Real-time dashboard
Deduplication built in
Free trial — no card
* Industry average based on publicly listed pricing of ZeroBounce, NeverBounce, Hunter, and Emailable at time of writing.
Built for developers

One endpoint. The whole validator.

One POST, a Bearer token, and a JSON body. You get a verdict, a machine-readable status, and your remaining credits in under 200ms. No SDK lock-in, no GraphQL, no surprises.

Endpoint
POST· application/json
https://api.mailboxverifier.com/v1/validate
AuthorizationBearer ev_…
Content-Typeapplication/json
Body{ "email": "..." }
Get your API key
100 free credits · no card
request.sh
3 lines · 1 request
curl -X POST https://api.mailboxverifier.com/v1/validate \
  -H "Authorization: Bearer ev_3f7c2a91b4e8d6f0" \
  -H "Content-Type: application/json" \
  -d '{"email":"founder@stripe.com"}'
Response · 200 · valid
JSON
{
  "email": "founder@stripe.com",
  "status": "valid",
  "code": 1,
  "message": "OK",
  "creditsRemaining": 49831
}
Response · 200 · invalid
JSON
{
  "email": "dead@nobody.invalid",
  "status": "invalid",
  "code": 2,
  "message": "Mailbox does not exist",
  "creditsRemaining": 49830
}
Response codes

Four statuses. That's the whole vocabulary.

valid
HTTP 200
Address is deliverable. Safe to send.
invalid
HTTP 200
Mailbox, MX or syntax check failed. Will bounce.
catchall
HTTP 200
Server accepts all mail. Use with caution.
error
HTTP 4
Rate-limited, invalid key, or upstream issue.
99.99% uptimeRate-limit headers on every responseWebhook callbacks — coming Q3
Pricing

One plan.
The whole product.

We don't do tiers, add-ons, or "contact sales". You get everything for a flat $49/month.

Everything in the platform
$
49
/ month·billed monthly
$499Save 90%
No credit card · Cancel anytime
What's inside
7 / 7
  • 1,000 free credits to try
  • 50,000 daily credits
  • Bulk list cleaning
  • Single email verification
  • API access
  • Enterprise-grade accuracy
  • Credit top-ups available
What's not inside
  • Annual lock-in
  • Seat fees
  • Usage-tier upsell calls
  • Hidden per-feature paywalls

30× more affordable than the cheapest competitor. · Try it free. If we're not the best validator you've ever used, keep your data.

FAQ

Questions we get a lot.

Can't find what you're looking for? Email hi@mailboxverifier.com — a real person will write back.

We score 98.42% on our labelled 100,000-address test set, retested weekly. That's a measured number, not a marketing one. We publish precision, recall, and F1 in the dashboard.
Three things, in order: syntax, MX records, then a real SMTP handshake. The result is tagged valid, invalid, or catch-all. We also surface the SMTP response code, the MX host, and the user / domain split so you can debug.
Yes. Sign up with your email, get free credits, verify a list, and decide. No credit card required, no sales call, no 'schedule a demo to unlock' nonsense.
One full verification — syntax + MX + SMTP. We don't split those into separate credit tiers. If you upload a CSV with 10,000 rows, that's 10,000 credits.
Your 50,000 daily credits reset every 24 hours — that's how we keep the price this low. If you need a different cadence (e.g. monthly), reach out and we'll work it out.
Your data is yours. We store it in your dashboard so you can re-verify, re-export, or delete it whenever you want. We never use your lists to train anything and we never sell them. Ever.
Not yet. We're heads-down on the web product right now. If you need programmatic access for a serious volume, drop us a line and we'll figure it out.
Yes — one click from your settings. No retention call, no "are you sure" survey, no prorated refund fight. Cancel and you're out.
Because email validation is a solved problem and the margins on it are absurd. The big players charge 30–100× markup because they can. We can charge 1× and still make plenty. We'd rather have a million happy customers than ten thousand overcharged ones.
Free trial · 100 credits · no card

Stop overpaying
for valid emails.

50,000 daily verifications. 98.42% accuracy. $49 a month.
If that sounds too good, start the free trial and prove us wrong.

app.mailboxverifier.com·No card required·Cancel in one click·SOC 2 in progress