Verify one address
or your whole list

Paste a list, upload a CSV, or call the API from your backend. Every check runs syntax, MX records and a real SMTP mailbox probe — in France, with nothing stored.

Try it free, 15 checks/day. Sign up for 100 credits

If the Verify button stays greyed out, the verifier did not load — reload the page.

Clean a list, no code

Paste up to 500 addresses, or upload a CSV of up to 10 MB and 250,000 addresses. It runs in the background and emails you a downloadable CSV when it is done.

Start with 100 free credits

Integrate the API

One POST, up to 20 addresses per call, JSON back in seconds. Bearer token, no OAuth dance, examples in curl, Node.js, Python, PHP and Go.

Read the API docs

Request

curl -X POST https://mailprobe.dev/api/v1/verify \
  -H "authorization: Bearer mp_live_..." \
  -H "content-type: application/json" \
  -d '{"emails":["alex@acme.co"]}'

Response ~1.2s

[{
  "email": "alex@acme.co",
  "result": "deliverable",
  "status": "valid",
  "score": 92,
  "syntax": true,
  "mx_found": true,
  "smtp_check": true,
  "disposable": false,
  "role_based": false,
  "free_provider": false,
  "mx_records": ["mx.acme.co"]
}]

What you get

Syntax Validation

RFC-compliant email format check before hitting any server.

MX Record Lookup

Verify the domain has valid mail exchange servers configured.

SMTP Handshake

Connect to the mail server and check if the mailbox exists, without sending an email.

Disposable Detection

Flag temporary email addresses from known disposable providers.

Role-Based Detection

Identify generic addresses like admin@, info@, support@ that often bounce.

Catch-All Detection

Know when a server accepts all addresses regardless of existence.

How MailProbe works

Four steps from signup to a clean email list, no config, no infrastructure to run. Want a result before signing up? The free email verifier runs the same engine, no account needed.

1

Sign up in seconds

Magic-link login, no password. You get 100 free credits, enough to verify your own mailing list and judge the accuracy first-hand before spending anything.
2

Bring your addresses

Paste up to 500 in your account, upload a CSV, or take an API key from your dashboard to send them from your backend. Up to 10 keys per account, rotate any of them at any time, no OAuth dance and no IP whitelisting.
3

Let it run

A pasted list or an uploaded file runs in the background and emails you a downloadable CSV when it is done. From a backend, a single POST /api/v1/verify returns up to 20 results in seconds, with status, reason and SMTP codes.
4

Act on the result

Block invalid signups, remove dead addresses before your next campaign, or flag catch-all domains as "risky" in your CRM. Every verification is a saved bounce and a protected sender reputation.

Who uses MailProbe

Built for teams that send email for a living and can't afford a blocked domain.

SaaS & product teams

Verify emails at signup to kill fake accounts, trial abusers, and disposable inboxes before they pollute your metrics and waste onboarding emails.

Email marketers

Clean your list before every campaign. Cut bounce rate below 2% so Gmail, Outlook, and Yahoo keep delivering you to the inbox instead of the promotions tab, or worse.

Developers

Drop in real-time validation on contact forms, lead magnets, and newsletter signups. One HTTP call replaces regex patterns that miss 60% of invalid addresses.

Agencies & consultants

Clean imported client lists before you run a single send. Deliver measurable open-rate lifts in week one, justify the retainer from day one.

Privacy-first, EU-resident by design

Most verifiers are US companies that store what you check. MailProbe is the opposite — your data stays in Europe and is never kept.

EU-hosted infrastructure

Every verification runs on servers in France (OVH). Your list never leaves the European Union.

Zero result storage

We never store, cache, or log the addresses you verify. Every check is fresh, then gone — nothing retained, sold, or shared.

No CLOUD Act exposure

MailProbe is EU-operated. Unlike US-domiciled verifiers, your data isn't subject to US government access requests.

MailProbe vs alternatives

Email verification doesn't need to be complicated or subscription-locked.

Feature	MailProbe	ZeroBounce	NeverBounce	DIY regex
Real-time API	✓	✓	✓	✗
SMTP handshake	✓	✓	✓	✗
Catch-all detection	✓	✓	✓	✗
Disposable & role-based	✓	✓	✓	Partial
Pay per use	✓ credits	Monthly plan	Monthly plan	—
Starts at (per check)	$0.0015	~$0.007	~$0.008	Free
Free credits on signup	100	100	1,000	—
Credits expire	1 year (reset on purchase)	Annually	Annually	—
CSV upload + bulk API (up to 500/call)	✓	✓	✓	✗

Don't take our word for it. Test with the 100 free credits on signup before committing a single dollar.

Why this matters

A stale email list isn't just noise; it silently degrades every campaign you send.

5–15%

invalid rate on purchased or old lists

Industry average for lists acquired via lead magnets, imported from CRMs, or left untouched for 12+ months. MailProbe catches them before your ESP does.

> 5%

bounce rate triggers throttling

Gmail, Outlook, and Yahoo penalize senders who bounce heavily. Once your reputation drops, recovery takes weeks, assuming the damage isn't permanent.

Seconds

per verification, not minutes

Fast enough to block invalid signups in real-time on form submissions, and batches of hundreds of addresses finish while you refill your coffee.

$20

buys 10,000 verifications

One cleaned campaign to an acquired list often pays for a full year of MailProbe credits. Credits stay valid for a full year and reset on every top-up. You only spend them when you check an address.

Simple pricing

Pay per use, no subscription. 100 credits free on signup, then from $5 for 1,000 verifications down to $0.0015 each at volume. Credits stay valid 12 months.

See full pricing

Built in the open, by devs who ship

MailProbe is new. Rather than fake testimonials, here's exactly what you're buying into.

Response time

~1.2s

Median verification latency, measured on live production traffic across typical consumer and B2B domains.

Transparency

Fullreason codes

Every response includes the exact check that returned the verdict: mailbox_exists, no_mx, disposable, catch_all, smtp_reject. No black box.

No lock-in

$0to start

100 credits on signup, no credit card. Credits never recur; you only spend what you explicitly top up, and they carry forward for a rolling 12 months.

Operated by Iris Digital, same team running Praticulus, AskQuiz, and the rest of the network. The verification engine powers our internal email workflows before it's exposed here.

Frequently Asked Questions

How does MailProbe verify email addresses?

MailProbe performs real-time SMTP-level verification: syntax check, MX lookup, domain validation, catch-all detection, and deliverability check, all without sending an actual email.

Is the verification reliable?

Yes. We check syntax, DNS/MX records, and perform SMTP-level validation. Catch-all domains are flagged as "risky" rather than guessed, so you avoid false positives that would waste your send reputation.

Do you store the emails I verify?

No. The addresses you submit are processed in memory and discarded when the response is returned, and no result is ever cached — every request re-probes live. We keep aggregated technical logs for up to 90 days to monitor the service; they contain the recipient domain and the result code, never the address itself. Nothing is shared with third parties or used for any other purpose.

How do the credit packs differ?

Only in size, and therefore in unit price: the larger the pack, the cheaper the address, from $0.005 down to $0.0015. Every pack unlocks exactly the same thing — full API access, the batch screen and the dashboard — and credits stay valid 12 months, renewed on each top-up. The four packs and their prices are on the pricing page.

How does the API work?

Single POST /api/v1/verify with your API key as a Bearer token in the Authorization header and the emails in the JSON body. Returns a JSON array with result (deliverable, undeliverable, catch-all, unknown), an actionable status (valid, invalid, risky, unknown), a 0–100 score, and diagnostic flags (syntax, mx_found, smtp_check, disposable, role_based, free_provider, mx_records). Full documentation at /api-docs/.

Can I verify a bulk list of emails?

Yes, and you don't need to write code for it. Paste a list of up to 500 addresses in your account, or upload a CSV or TXT file of up to 10 MB and 250,000 addresses per batch — the list runs in the background and you get an email with a downloadable CSV when it's done. From a backend, send an array of up to 20 addresses to POST /api/v1/verify and get the results in the response. Credits are deducted per address verified, not per call.

Do credits expire?

Credits stay valid for one year from your most recent purchase, and the clock resets every time you top up. No subscription, no recurring charge, just a rolling 12-month window that regenerates as long as you stay active.

Why should I verify emails before sending?

Invalid addresses cause bounces, and bounces above 5% get your domain throttled or flagged as spam by Gmail, Outlook, and Yahoo. Verifying upfront protects your sender reputation, improves deliverability across every future campaign, and stops you from paying your ESP to send to addresses that don't exist.

How accurate is email verification?

MailProbe achieves >98% accuracy on valid/invalid calls on typical lists. Catch-all domains (where the server accepts every address) are inherently unverifiable without actually sending, so we flag those as "risky" instead of guessing, so you can decide whether to include them.

What's the difference between valid, invalid, and risky?

Valid = the mailbox exists and accepts mail. Invalid = syntax fails, domain has no MX records, or the mailbox explicitly rejects. Risky = technically accepted but uncertain (catch-all domains, role-based addresses like info@, disposable providers, or Microsoft consumer domains like outlook.com and hotmail.com, which block SMTP probing outright). This is the status field, and every result also carries a 0–100 score so you can threshold per campaign. Most teams send to valid only and skip risky on cold campaigns.

Can I use MailProbe for real-time form validation?

Yes, verifications typically complete in a couple of seconds, fast enough to block invalid signups on form submission. Keep the API key server-side (never expose it in client-side JS), and proxy the request from your backend.

Is MailProbe GDPR-compliant?

Yes. The email addresses you verify are never stored: they are processed in real time and discarded once the response is sent. Nothing is shared, sold, or reused, and every verification runs on servers in France (OVH), so your list never leaves the EU. Full details on the privacy page.

Does verifying an email count as sending one?

No. MailProbe opens an SMTP connection with the recipient's mail server and asks "does this mailbox exist?" without ever transmitting a message. The recipient receives nothing: no email, no notification, no trace in their inbox.

What programming languages are supported?

Any language that can make an HTTP request, so all of them. The API is a plain POST /api/v1/verify that returns JSON. We show copy-paste examples for curl, Node.js, Python, PHP, and Go in the API docs.

What happens if I run out of credits mid-batch?

The API returns a 402 Payment Required response. Your batch stops cleanly; we don't charge for requests we couldn't fulfill. Top up from the dashboard and resume where you left off.

Verify one addressor your whole list